1
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Gaikwad PB, Kim TD, Richer M, Lokhande RA, Sánchez-Díaz G, Limacher PA, Ayers PW, Miranda-Quintana RA. Coupled cluster-inspired geminal wavefunctions. J Chem Phys 2024; 160:144108. [PMID: 38597308 DOI: 10.1063/5.0202035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 03/24/2024] [Indexed: 04/11/2024] Open
Abstract
Electron pairs have an illustrious history in chemistry, from powerful concepts to understanding structural stability and reactive changes to the promise of serving as building blocks of quantitative descriptions of the electronic structure of complex molecules and materials. However, traditionally, two-electron wavefunctions (geminals) have not enjoyed the popularity and widespread use of the more standard single-particle methods. This has changed recently, with a renewed interest in the development of geminal wavefunctions as an alternative to describing strongly correlated phenomena. Hence, there is a need to find geminal methods that are accurate, computationally tractable, and do not demand significant input from the user (particularly via cumbersome and often ill-behaved orbital optimization steps). Here, we propose new families of geminal wavefunctions inspired by the pair coupled cluster doubles ansatz. We present a new hierarchy of two-electron wavefunctions that extends the one-reference orbital idea to other geminals. Moreover, we show how to incorporate single-like excitations in this framework without leaving the quasiparticle picture. We explore the role of imposing seniority restrictions on these wavefunctions and benchmark these new methods on model strongly correlated systems.
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Affiliation(s)
- Pratiksha B Gaikwad
- Department of Chemistry and Quantum Theory Project, University of Florida, Gainesville, Florida 32603, USA
| | - Taewon D Kim
- Department of Chemistry and Quantum Theory Project, University of Florida, Gainesville, Florida 32603, USA
| | - M Richer
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Rugwed A Lokhande
- Department of Chemistry and Quantum Theory Project, University of Florida, Gainesville, Florida 32603, USA
| | - Gabriela Sánchez-Díaz
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Peter A Limacher
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Paul W Ayers
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada
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2
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Pathirage PDVS, Phillips JT, Vogiatzis KD. Exploration of the Two-Electron Excitation Space with Data-Driven Coupled Cluster. J Phys Chem A 2024. [PMID: 38422511 DOI: 10.1021/acs.jpca.3c06600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Computational cost limits the applicability of post-Hartree-Fock methods such as coupled-cluster on larger molecular systems. The data-driven coupled-cluster (DDCC) method applies machine learning to predict the coupled-cluster two-electron amplitudes (t2) using data from second-order perturbation theory (MP2). One major limitation of the DDCC models is the size of training sets that increases exponentially with the system size. Effective sampling of the amplitude space can resolve this issue. Five different amplitude selection techniques that reduce the amount of data used for training were evaluated, an approach that also prevents model overfitting and increases the portability of data-driven coupled-cluster singles and doubles to more complex molecules or larger basis sets. In combination with a localized orbital formalism to predict the CCSD t2 amplitudes, we have achieved a 10-fold error reduction for energy calculations.
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Affiliation(s)
- P D Varuna S Pathirage
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996-1600, United States
| | - Justin T Phillips
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996-1600, United States
| | - Konstantinos D Vogiatzis
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996-1600, United States
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3
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Yang S, Zhang IY, Ren X. Developing correlation-consistent numeric atom-centered orbital basis sets for krypton: Applications in RPA-based correlated calculations. J Chem Phys 2024; 160:024112. [PMID: 38193553 DOI: 10.1063/5.0174952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 12/04/2023] [Indexed: 01/10/2024] Open
Abstract
Localized atomic orbitals are the preferred basis set choice for large-scale explicit correlated calculations, and high-quality hierarchical correlation-consistent basis sets are a prerequisite for correlated methods to deliver numerically reliable results. At present, numeric atom-centered orbital (NAO) basis sets with valence correlation consistency (VCC), designated as NAO-VCC-nZ, are only available for light elements from hydrogen (H) to argon (Ar) [Zhang et al., New J. Phys. 15, 123033 (2013)]. In this work, we extend this series by developing NAO-VCC-nZ basis sets for krypton (Kr), a prototypical element in the fourth row of the periodic table. We demonstrate that NAO-VCC-nZ basis sets facilitate the convergence of electronic total-energy calculations using the Random Phase Approximation (RPA), which can be used together with a two-point extrapolation scheme to approach the complete basis set limit. Notably, the Basis Set Superposition Error (BSSE) associated with the newly generated NAO basis sets is minimal, making them suitable for applications where BSSE correction is either cumbersome or impractical to do. After confirming the reliability of NAO basis sets for Kr, we proceed to calculate the Helmholtz free energy for Kr crystal at the theoretical level of RPA plus renormalized single excitation correction. From this, we derive the pressure-volume (P-V) diagram, which shows excellent agreement with the latest experimental data. Our work demonstrates the capability of correlation-consistent NAO basis sets for heavy elements, paving the way toward numerically reliable correlated calculations for bulk materials.
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Affiliation(s)
- Sixian Yang
- Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Igor Ying Zhang
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai, Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Shanghai Key Laboratory of Bioactive Small Molecules, Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Xinguo Ren
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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4
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Corzo HH, Hillers-Bendtsen AE, Barnes A, Zamani AY, Pawłowski F, Olsen J, Jørgensen P, Mikkelsen KV, Bykov D. Corrigendum: Coupled cluster theory on modern heterogeneous supercomputers. Front Chem 2023; 11:1256510. [PMID: 37654900 PMCID: PMC10466216 DOI: 10.3389/fchem.2023.1256510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 09/02/2023] Open
Abstract
[This corrects the article DOI: 10.3389/fchem.2023.1154526.].
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Affiliation(s)
| | | | | | - Abdulrahman Y. Zamani
- Department of Chemistry and Biochemistry and Center for Chemical Computation and Theory, University of California, Merced, CA, United States
| | - Filip Pawłowski
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL, United States
| | - Jeppe Olsen
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | - Poul Jørgensen
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | - Kurt V. Mikkelsen
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Dmytro Bykov
- Oak Ridge National Laboratory, Oak Ridge, TN, United States
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5
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Corzo HH, Hillers-Bendtsen AE, Barnes A, Zamani AY, Pawłowski F, Olsen J, Jørgensen P, Mikkelsen KV, Bykov D. Coupled cluster theory on modern heterogeneous supercomputers. Front Chem 2023; 11:1154526. [PMID: 37388945 PMCID: PMC10303140 DOI: 10.3389/fchem.2023.1154526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/11/2023] [Indexed: 07/01/2023] Open
Abstract
This study examines the computational challenges in elucidating intricate chemical systems, particularly through ab-initio methodologies. This work highlights the Divide-Expand-Consolidate (DEC) approach for coupled cluster (CC) theory-a linear-scaling, massively parallel framework-as a viable solution. Detailed scrutiny of the DEC framework reveals its extensive applicability for large chemical systems, yet it also acknowledges inherent limitations. To mitigate these constraints, the cluster perturbation theory is presented as an effective remedy. Attention is then directed towards the CPS (D-3) model, explicitly derived from a CC singles parent and a doubles auxiliary excitation space, for computing excitation energies. The reviewed new algorithms for the CPS (D-3) method efficiently capitalize on multiple nodes and graphical processing units, expediting heavy tensor contractions. As a result, CPS (D-3) emerges as a scalable, rapid, and precise solution for computing molecular properties in large molecular systems, marking it an efficient contender to conventional CC models.
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Affiliation(s)
| | | | | | - Abdulrahman Y. Zamani
- Department of Chemistry and Biochemistry and Center for Chemical Computation and Theory, University of California, Merced, CA, United States
| | - Filip Pawłowski
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL, United States
| | - Jeppe Olsen
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | - Poul Jørgensen
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | - Kurt V. Mikkelsen
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Dmytro Bykov
- Oak Ridge National Laboratory, Oak Ridge, TN, United States
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6
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Izsák R, Ivanov AV, Blunt NS, Holzmann N, Neese F. Measuring Electron Correlation: The Impact of Symmetry and Orbital Transformations. J Chem Theory Comput 2023; 19:2703-2720. [PMID: 37022051 PMCID: PMC10210250 DOI: 10.1021/acs.jctc.3c00122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Indexed: 04/07/2023]
Abstract
In this perspective, the various measures of electron correlation used in wave function theory, density functional theory and quantum information theory are briefly reviewed. We then focus on a more traditional metric based on dominant weights in the full configuration solution and discuss its behavior with respect to the choice of the N-electron and the one-electron basis. The impact of symmetry is discussed, and we emphasize that the distinction among determinants, configuration state functions and configurations as reference functions is useful because the latter incorporate spin-coupling into the reference and should thus reduce the complexity of the wave function expansion. The corresponding notions of single determinant, single spin-coupling and single configuration wave functions are discussed and the effect of orbital rotations on the multireference character is reviewed by analyzing a simple model system. In molecular systems, the extent of correlation effects should be limited by finite system size and in most cases the appropriate choices of one-electron and N-electron bases should be able to incorporate these into a low-complexity reference function, often a single configurational one.
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Affiliation(s)
- Róbert Izsák
- Riverlane, St Andrews House, 59 St Andrews
Street, Cambridge CB2 3BZ, United Kingdom
| | - Aleksei V. Ivanov
- Riverlane, St Andrews House, 59 St Andrews
Street, Cambridge CB2 3BZ, United Kingdom
| | - Nick S. Blunt
- Riverlane, St Andrews House, 59 St Andrews
Street, Cambridge CB2 3BZ, United Kingdom
| | - Nicole Holzmann
- Riverlane, St Andrews House, 59 St Andrews
Street, Cambridge CB2 3BZ, United Kingdom
| | - Frank Neese
- Max-Planck
Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
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7
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Echeverri A, Gallegos M, Gómez T, Pendás ÁM, Cárdenas C. Calculation of the ELF in the excited state with single-determinant methods. J Chem Phys 2023; 158:2887544. [PMID: 37125705 DOI: 10.1063/5.0142918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/17/2023] [Indexed: 05/02/2023] Open
Abstract
Since its first definition, back in 1990, the electron localization function (ELF) has settled as one of the most commonly employed techniques to characterize the nature of the chemical bond in real space. Although most of the work using the ELF has focused on the study of ground-state chemical reactivity, a growing interest has blossomed to apply these techniques to the nearly unexplored realm of excited states and photochemistry. Since accurate excited electronic states usually require to account appropriately for electron correlation, the standard single-determinant ELF formulation cannot be blindly applied to them, and it is necessary to turn to correlated ELF descriptions based on the two-particle density matrix (2-PDM). The latter requires costly wavefunction approaches, unaffordable for most of the systems of current photochemical interest. Here, we compare the exact, 2-PDM-based ELF results with those of approximate 2-PDM reconstructions taken from reduced density matrix functional theory. Our approach is put to the test in a wide variety of representative scenarios, such as those provided by the lowest-lying excited electronic states of simple diatomic and polyatomic molecules. Altogether, our results suggest that even approximate 2-PDMs are able to accurately reproduce, on a general basis, the topological and statistical features of the ELF scalar field, paving the way toward the application of cost-effective methodologies, such as time-dependent-Hartree-Fock or time-dependent density functional theory, in the accurate description of the chemical bonding in excited states of photochemical relevance.
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Affiliation(s)
- Andrea Echeverri
- Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
| | - Miguel Gallegos
- Depto. Química Física y Analítica, Universidad de Oviedo, 33006 Oviedo, Spain
| | - Tatiana Gómez
- Theoretical and Computational Chemistry Center, Institute of Applied Chemical Sciences, Faculty of Engineering, Universidad Autonoma de Chile, El Llano Subercaceaux, 2801 Santiago, Chile
| | - Ángel Martín Pendás
- Depto. Química Física y Analítica, Universidad de Oviedo, 33006 Oviedo, Spain
| | - Carlos Cárdenas
- Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
- Centro para el Desarrollo de la Nanociencia y la Nanotecnología (CEDENNA), Avda. Ecuador 3493, Santiago 9170124, Chile
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8
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Kuntz D, Wilson AK. Machine learning, artificial intelligence, and chemistry: how smart algorithms are reshaping simulation and the laboratory. PURE APPL CHEM 2022. [DOI: 10.1515/pac-2022-0202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Machine learning and artificial intelligence are increasingly gaining in prominence through image analysis, language processing, and automation, to name a few applications. Machine learning is also making profound changes in chemistry. From revisiting decades-old analytical techniques for the purpose of creating better calibration curves, to assisting and accelerating traditional in silico simulations, to automating entire scientific workflows, to being used as an approach to deduce underlying physics of unexplained chemical phenomena, machine learning and artificial intelligence are reshaping chemistry, accelerating scientific discovery, and yielding new insights. This review provides an overview of machine learning and artificial intelligence from a chemist’s perspective and focuses on a number of examples of the use of these approaches in computational chemistry and in the laboratory.
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Affiliation(s)
- David Kuntz
- Department of Chemistry , University of North Texas , Denton , TX 76201 , USA
| | - Angela K. Wilson
- Department of Chemistry , Michigan State University , East Lansing , MI 48824 , USA
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9
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Ahsan MS, Kochetov V, Hein D, Bokarev SI, Wilkinson I. Probing the molecular structure of aqueous triiodide via X-ray photoelectron spectroscopy and correlated electron phenomena. Phys Chem Chem Phys 2022; 24:15540-15555. [PMID: 35713286 DOI: 10.1039/d1cp05840a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Liquid-microjet-based X-ray photoelectron spectroscopy was applied to aqueous triiodide solutions, I3-(aq.), to investigate the anion's valence- and core-level electronic structure, ionization dynamics, associated electron-correlation effects, and nuclear geometric structure. The roles of multi-active-electron (shake-up) ionization processes - with noted sensitivity to the solute geometric structure - were investigated through I3-(aq.) solution valence, I 4d, and I 3d core-level measurements. The experimental spectra were interpreted with the aid of simulated photoelectron spectra, built upon multi-reference ab initio electronic structure calculations associated with different I3-(aq.) molecular geometries. A comparison of the single-to-multi-active-electron ionization signal ratios extracted from the experimental and theoretical core-level photoemission spectra suggests that the ground state of the solute adopts a near-linear average geometry in aqueous solutions. This contrasts with the interpretation of time-resolved X-ray solution scattering studies, but is found to be fully consistent with the rest of the solution-phase I3-(aq.) literature. Comparing the results of low- and high-photon-energy photoemission measurements, we further suggest that the aqueous anion adopts a more asymmetric geometry at the aqueous-solution-gas interface than in the aqueous bulk.
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Affiliation(s)
- Md Sabbir Ahsan
- Department of Locally-Sensitive and Time-Resolved Spectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany. .,Department of Physics, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Vladislav Kochetov
- Institut für Physik, Universität Rostock, Albert Einstein Str. 23-24, D-18059 Rostock, Germany
| | - Dennis Hein
- Operando Interfacial Photochemistry, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-platz. 1, D-14109 Berlin, Germany.,Department of Physics, Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin, Germany
| | - Sergey I Bokarev
- Institut für Physik, Universität Rostock, Albert Einstein Str. 23-24, D-18059 Rostock, Germany
| | - Iain Wilkinson
- Department of Locally-Sensitive and Time-Resolved Spectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.
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10
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Mitxelena I, Piris M. Benchmarking GNOF against FCI in challenging systems in one, two, and three dimensions. J Chem Phys 2022; 156:214102. [DOI: 10.1063/5.0092611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This work assesses the reliability of the recently proposed [M. Piris, Phys. Rev. Lett. 127, 233001 (2021)] global natural orbital functional (GNOF) in the treatment of the strong electron correlation regime. First, we use an H10 benchmark set of four hydrogen model systems of different dimensionalities and distinctive electronic structures: a 1D chain, a 2D ring, a 2D sheet, and a 3D close-packed pyramid. Second, we study two paradigmatic models for strongly correlated Mott insulators, namely, a 1D H50 chain and a 4 × 4 × 4 3D H cube. We show that GNOF, without hybridization to other electronic structure methods and free of tuned parameters, succeeds in treating weak and strong correlation in a more balanced way than the functionals that have preceded it.
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Affiliation(s)
- Ion Mitxelena
- Donostia International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain
- Euskal Herriko Unibertsitatea (UPV/EHU), PK 1072, 20080 Donostia, Euskadi, Spain
| | - Mario Piris
- Donostia International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain
- Euskal Herriko Unibertsitatea (UPV/EHU), PK 1072, 20080 Donostia, Euskadi, Spain
- Basque Foundation for Science (IKERBASQUE), 48009 Bilbao, Euskadi, Spain
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11
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Quantum Chemical Approaches to the Calculation of NMR Parameters: From Fundamentals to Recent Advances. MAGNETOCHEMISTRY 2022. [DOI: 10.3390/magnetochemistry8050050] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Quantum chemical methods for the calculation of indirect NMR spin–spin coupling constants and chemical shifts are always in progress. They never stay the same due to permanently developing computational facilities, which open new perspectives and create new challenges every now and then. This review starts from the fundamentals of the nonrelativistic and relativistic theory of nuclear magnetic resonance parameters, and gradually moves towards the discussion of the most popular common and newly developed methodologies for quantum chemical modeling of NMR spectra.
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12
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Via-Nadal M, Rodríguez Mayorga MA, Ramos Cordoba E, Matito E. Natural Range Separation of the Coulomb Hole. J Chem Phys 2022; 156:184106. [DOI: 10.1063/5.0085284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A natural range separation of the Coulomb hole into two components, one of them being predominant at long interelectronic separations (hcI ) and the other at short distances (hcII ), is exhaustively analyzed throughout various examples that put forward the most relevant features of this approach and how they can be used to develop efficient ways to capture electron correlation. We show that hcI, which only depends on the first-order reduced density matrix, can be used to identify molecules with a predominant nondynamic correlation regime and differentiate between two types of nondynamic correlation, types A and B. Through the asymptotic properties of the hole components, we explain how hcI can retrieve the long-range part of electron correlation. We perform an exhaustive analysis of the hydrogen molecule in a minimal basis set, dissecting the hole contributions into spin components. We also analyze the simplest molecule presenting a dispersion interaction and how hcII helps identify it. The study of several atoms in different spin states reveals that the Coulomb hole components distinguish correlation regimes that are not apparent from the entire hole. The results of this work hold out the promise to aid in developing new electronic structure methods that efficiently capture electron correlation.
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Affiliation(s)
| | | | - Eloy Ramos Cordoba
- Theoretical Chemistry Group, Donostia International Physics Center, Spain
| | - Eduard Matito
- Donostia International Physics Center, Donostia International Physics Center, Spain
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13
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Traore D, Giner E, Toulouse J. Basis-set correction based on density-functional theory: Rigorous framework for a one-dimensional model. J Chem Phys 2022; 156:044113. [DOI: 10.1063/5.0076128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Diata Traore
- Laboratoire de Chimie Théorique, Sorbonne Université and CNRS, F-75005 Paris, France
| | - Emmanuel Giner
- Laboratoire de Chimie Théorique, Sorbonne Université and CNRS, F-75005 Paris, France
| | - Julien Toulouse
- Laboratoire de Chimie Théorique, Sorbonne Université and CNRS, F-75005 Paris, France
- Institut Universitaire de France, F-75005 Paris, France
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14
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Mercero JM, Ugalde JM. Electronic Structure and Electron Delocalization in Bare and Dressed Boron Pentamer Clusters. J Phys Chem A 2021; 125:5246-5255. [PMID: 34114818 PMCID: PMC9159651 DOI: 10.1021/acs.jpca.1c02305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
The
electronic structures of the lowest energy spin-states of the cationic,
neutral and anionic bare boron pentamer clusters have been investigated
by means of high level multiconfigurational type calculations, in
view of the large static and dynamical electron correlation effects
for these species. We found that resembles a singlet
spin-state perfect pentagon, which bears no intra-annular chemical
bonding interactions, as shown by our analysis of the electron delocalization
carried out in terms of the normalized Giambiagi ring-current index,
and the total and adjacent atom-pair delocalization indices. However,
its lowest-energy triplet and quintet spin-state isomers have C2v symmetry, with large intra-annular
chemical bonding interactions. This geometrical feature extends to
both the neutral and the anionic species. Namely, the lowest-energy
isomers of boron pentamer neutral and anionic clusters have peripheral
and intra-annular sizable bonding interactions reflected in the delocalization
of both π- and σ-type valence natural orbitals over the
whole molecular plane, which impart large structural stability. In
accordance to our calculations, the lowest energy triplet spin-state
isomer of the anionic boron pentamer cluster has C2 symmetry, and consequently, it should show optical activity.
Finally, we have studied the change of the geometrical structure of
the boron pentamer clusters from planar to compact three-dimensional
structures caused by the bonding of ligands to the boron atoms. Our
explicit all-electron calculations have been rationalized in terms
of the shell-closure of the delocalized valence orbitals of the clusters
as predicted by the jellium model extended to nonspherical confinement
potentials, circumscribing the role of the ligand to modulate the
total number of valence electrons assigned to the core cluster.
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Affiliation(s)
- Jose M Mercero
- Kimika Fakultatea, Euskal Herriko Unbertsitatea (UPV/EHU), Donostia International Physics Center (DIPC), P.K. 1072, 20080 Donostia, Euskadi, Spain
| | - Jesus M Ugalde
- Kimika Fakultatea, Euskal Herriko Unbertsitatea (UPV/EHU), Donostia International Physics Center (DIPC), P.K. 1072, 20080 Donostia, Euskadi, Spain
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15
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Todd LG, Hollett JW. Measuring correlated electron motion in atoms with the momentum-balance density. J Chem Phys 2021; 154:074110. [PMID: 33607904 DOI: 10.1063/5.0039387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Three new measures of relative electron motion are introduced: equimomentum, antimomentum, and momentum-balance. The equimomentum is the probability that two electrons have the exact same momentum, whereas the antimomentum is the probability that their momenta are the exact opposite. Momentum-balance (MB) is the difference between the equimomentum and antimomentum and, therefore, indicates if equal or opposite momentum is more probable in a system of electrons. The equimomentum, antimomentum, and MB densities are also introduced, which are the local contribution to each quantity. The MB and MB density of the extrapolated-full configuration interaction wave functions of atoms of the first three rows of the periodic table are analyzed, with a particular focus on contrasting the correlated motion of electrons with opposite-spin and parallel-spin. Coulomb correlation between opposite-spin electrons leads to a higher probability of equimomentum, whereas Fermi correlation between parallel-spin electrons leads to a higher probability of antimomentum. The local contribution to MB, given an electron is present, is a minimum at the nucleus and generally increases as the distance from the nucleus increases. There are also interesting similarities between the effects of Fermi correlation and Coulomb correlation (of opposite-spin electrons) on MB.
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Affiliation(s)
- Lucy G Todd
- Department of Chemistry, University of Winnipeg, Winnipeg, Manitoba R3B 2E9, Canada
| | - Joshua W Hollett
- Department of Chemistry, University of Winnipeg, Winnipeg, Manitoba R3B 2E9, Canada
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16
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Zarotiadis RA, Burton HGA, Thom AJW. Towards a Holomorphic Density Functional Theory. J Chem Theory Comput 2020; 16:7400-7412. [PMID: 33211476 DOI: 10.1021/acs.jctc.0c00822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Self-consistent-field (SCF) approximations formulated using Hartree-Fock (HF) or Kohn-Sham density-functional theory (KS-DFT) have the potential to yield multiple solutions. However, the formal relationship between multiple solutions identified using HF or KS-DFT remains generally unknown. We investigate the connection between multiple SCF solutions for HF or KS-DFT by introducing a parameterized functional that scales between the two representations. Using the hydrogen molecule and a model of electron transfer, we continuously map multiple solutions from the HF potential to a KS-DFT description. We discover that multiple solutions can coalesce and vanish as the functional changes, forming a direct analogy with the disappearance of real HF solutions along a change in molecular structure. To overcome this disappearance of solutions, we develop a complex-analytic extension of DFT-the "holomorphic DFT" approach-that allows every SCF stationary state to be analytically continued across all molecular structures and exchange-correlation functionals.
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Affiliation(s)
- Rhiannon A Zarotiadis
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Hugh G A Burton
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.,Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ
| | - Alex J W Thom
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
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17
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Abstract
Applications of density-functional theory (DFT) in computational chemistry rely on an approximate exchange-correlation (xc) functional. However, existing approximations can fail dramatically for open-shell molecules, in particular for transition-metal complexes or radicals. Most importantly, predicting energy differences between different spin-states with approximate exchange-correlation functionals remains extremely challenging. Formally, it is known that the exact xc functional should be spin-state dependent, but none of the available approximations feature such an explicit spin-state dependence [C. R. Jacob and M. Reiher, Int. J. Quantum Chem., 2012, 112, 3661-3684]. Thus, to find novel approximations for the xc functional for open-shell systems, the development of spin-state dependent xc functionals appears to be a promising avenue. Here, we set out to shed light on the spin-state dependence of the xc functional by investigating the underlying xc holes, which we extract from configuration interaction calculations for model systems. We analyze the similarities and differences between the xc holes of the lowest-energy singlet and triplet states of the dihydrogen molecule, the helium atom, and the lithium dimer. To shed further light on the spin-state dependence of these xc holes we also discuss exact conditions that can be derived from the spin structure of the reduced two-electron density matrix. Altogether, our results suggest several possible routes towards the construction of explicitly spin-state dependent approximations for the xc functional.
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Affiliation(s)
- Julia Brüggemann
- Technische Universität Braunschweig, Institute of Physical and Theoretical Chemistry, Gaußstraße 17, 38106 Braunschweig, Germany.
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18
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Alipour M, Khorrami M. Pauli energy and information-theoretic approach for evaluating dynamic and nondynamic electron correlation. Theor Chem Acc 2020. [DOI: 10.1007/s00214-020-02689-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Stair NH, Evangelista FA. Exploring Hilbert space on a budget: Novel benchmark set and performance metric for testing electronic structure methods in the regime of strong correlation. J Chem Phys 2020; 153:104108. [DOI: 10.1063/5.0014928] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Affiliation(s)
- Nicholas H. Stair
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Francesco A. Evangelista
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
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20
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Warczinski L, Franke R, Staemmler V. ESCAPE: A novel approach for a fast estimation of dynamic correlation energies: Application to large organic molecules. J Comput Chem 2019; 40:2491-2501. [DOI: 10.1002/jcc.26025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/23/2019] [Accepted: 05/30/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Lisa Warczinski
- Lehrstuhl für Theoretische ChemieRuhr‐Universität Bochum Bochum Germany
| | - Robert Franke
- Lehrstuhl für Theoretische ChemieRuhr‐Universität Bochum Bochum Germany
- Evonik Performance Materials GmbH Paul‐Baumann‐Straße 1, Marl Germany
| | - Volker Staemmler
- Lehrstuhl für Theoretische ChemieRuhr‐Universität Bochum Bochum Germany
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21
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Schnack-Petersen AK, Haase PAB, Faber R, Provasi PF, Sauer SPA. RPA(D) and HRPA(D): Two new models for calculations of NMR indirect nuclear spin-spin coupling constants. J Comput Chem 2019; 39:2647-2666. [PMID: 30515901 DOI: 10.1002/jcc.25712] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/26/2018] [Accepted: 09/23/2018] [Indexed: 01/21/2023]
Abstract
In this article, the RPA(D) and HRPA(D) models for the calculation of linear response functions are presented. The performance of the new RPA(D) and HRPA(D) models is compared to the performance of the established RPA, HRPA, and SOPPA models in calculations of indirect nuclear spin-spin coupling constants using the CCSD model as a reference. The doubles correction offers a significant improvement on both the RPA and HRPA models; however, the improvement is more dramatic in the case of the RPA model. For all coupling types investigated in this study, the results obtained using the HRPA(D) model are comparable in accuracy to those given by the SOPPA model, while requiring between 30% and 90% of the calculation time needed for SOPPA. The RPA(D) model, while of slightly lower accuracy compared to the CCSD model than HRPA(D), offered calculation times of only approximately 25% of those required for SOPPA for all the investigated molecules. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Pi A B Haase
- Van Swinderen Institute, University of Groningen, Groningen, The Netherlands
| | - Rasmus Faber
- Department of Chemistry, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Patricio F Provasi
- Department of Physics-IMIT, Northeastern University-CONICET, Corrientes, Argentina
| | - Stephan P A Sauer
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
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22
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Truhlar DG, Hiberty PC, Shaik S, Gordon MS, Danovich D. Orbitals and the Interpretation of Photoelectron Spectroscopy and (e,2e) Ionization Experiments. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201904609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Donald G. Truhlar
- Department of Chemistry Chemical Theory Center, and Minnesota Supercomputing Institute University of Minnesota 207 Pleasant St. SE Minneapolis MN 55455-0431 USA
| | - Philippe C. Hiberty
- Laboratoire de Chimie Physique, CNRS UMR8000, Bat. 349 Université de Paris-Sud 91405 Orsay Cédex France
| | - Sason Shaik
- Institute of Chemistry The Hebrew University of Jerusalem Givant-Ram Campus Jerusalem 9190407 Israel
| | - Mark S. Gordon
- Department of Chemistry Iowa State University and Ames Laboratory Ames IA 50014 USA
| | - David Danovich
- Institute of Chemistry The Hebrew University of Jerusalem Givant-Ram Campus Jerusalem 9190407 Israel
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23
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Shen T, Zhu Z, Zhang IY, Scheffler M. Massive-Parallel Implementation of the Resolution-of-Identity Coupled-Cluster Approaches in the Numeric Atom-Centered Orbital Framework for Molecular Systems. J Chem Theory Comput 2019; 15:4721-4734. [DOI: 10.1021/acs.jctc.8b01294] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Tonghao Shen
- Department of Chemistry, Fudan University, Shanghai 200433, China
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Zhenyu Zhu
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Igor Ying Zhang
- Department of Chemistry, Fudan University, Shanghai 200433, China
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Science, Fudan University, Shanghai 200433, China
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Matthias Scheffler
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
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24
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Townsend J, Vogiatzis KD. Data-Driven Acceleration of the Coupled-Cluster Singles and Doubles Iterative Solver. J Phys Chem Lett 2019; 10:4129-4135. [PMID: 31290671 DOI: 10.1021/acs.jpclett.9b01442] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Solving the coupled-cluster (CC) equations is a cost-prohibitive process that exhibits poor scaling with system size. These equations are solved by determining the set of amplitudes (t) that minimize the system energy with respect to the coupled-cluster equations at the selected level of truncation. Here, a novel approach to predict the converged coupled-cluster singles and doubles (CCSD) amplitudes, thus the coupled-cluster wave function, is explored by using machine learning and electronic structure properties inherent to the MP2 level. Features are collected from quantum chemical data, such as orbital energies, one-electron Hamiltonian, Coulomb, and exchange terms. The data-driven CCSD (DDCCSD) is not an alchemical method because the actual iterative coupled-cluster equations are solved. However, accurate energetics can also be obtained by bypassing solving the CC equations entirely. Our preliminary data show that it is possible to achieve remarkable speedups in solving the CCSD equations, especially when the correct physics are encoded and used for training of machine learning models.
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Affiliation(s)
- Jacob Townsend
- Department of Chemistry , University of Tennessee , Knoxville , Tennessee 37996 , United States
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25
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Brito BGA, Hai GQ, Cândido L. Quantum Monte Carlo simulation for the many-body decomposition of the interaction energy and electron correlation of small superalkali lithium clusters. J Chem Phys 2019; 151:014303. [DOI: 10.1063/1.5099479] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- B. G. A. Brito
- Departamento de Física, Instituto de Ciências Exatas e Naturais e Educação (ICENE), Universidade Federal do Triângulo Mineiro - UFTM, 38064-200, Uberaba, MG, Brazil
| | - G.-Q. Hai
- Instituto de Física de São Carlos, Universidade de São Paulo, 13560-970, São Carlos, SP, Brazil
| | - L. Cândido
- Instituto de Física, Universidade Federal de Goiás - UFG, 74001-970, Goiânia, GO, Brazil
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26
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Truhlar DG, Hiberty PC, Shaik S, Gordon MS, Danovich D. Orbitals and the Interpretation of Photoelectron Spectroscopy and (e,2e) Ionization Experiments. Angew Chem Int Ed Engl 2019; 58:12332-12338. [PMID: 31081208 DOI: 10.1002/anie.201904609] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Indexed: 11/10/2022]
Abstract
Electron momentum spectroscopy, scanning tunneling microscopy, and photoelectron spectroscopy provide unique information about electronic structure, but their interpretation has been controversial. This essay discusses a framework for interpretation. Although this interpretation is not new, we believe it is important to present this framework in light of recent publications. The key point is that these experiments provide information about how the electron distribution changes upon ionization, not how electrons behave in the pre-ionized state. Therefore, these experiments do not lead to a "selection of the correct orbitals" in chemistry and do not overturn the well-known conclusion that both delocalized molecular orbitals and localized molecular orbitals are useful for interpreting chemical structure and dynamics. The two types of orbitals can produce identical total molecular electron densities and therefore molecular properties. Different types of orbitals are useful for different purposes.
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Affiliation(s)
- Donald G Truhlar
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN, 55455-0431, USA
| | - Philippe C Hiberty
- Laboratoire de Chimie Physique, CNRS UMR8000, Bat. 349, Université de Paris-Sud, 91405, Orsay Cédex, France
| | - Sason Shaik
- Institute of Chemistry, The Hebrew University of Jerusalem, Givant-Ram Campus, Jerusalem, 9190407, Israel
| | - Mark S Gordon
- Department of Chemistry, Iowa State University and Ames Laboratory, Ames, IA, 50014, USA
| | - David Danovich
- Institute of Chemistry, The Hebrew University of Jerusalem, Givant-Ram Campus, Jerusalem, 9190407, Israel
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27
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Böckers M, Franke R, Staemmler V. A heuristic estimate of molecular correlation energies using pair correlation energies of localized molecular orbitals. Theor Chem Acc 2019. [DOI: 10.1007/s00214-019-2422-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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28
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Vogiatzis KD, Polynski MV, Kirkland JK, Townsend J, Hashemi A, Liu C, Pidko EA. Computational Approach to Molecular Catalysis by 3d Transition Metals: Challenges and Opportunities. Chem Rev 2019; 119:2453-2523. [PMID: 30376310 PMCID: PMC6396130 DOI: 10.1021/acs.chemrev.8b00361] [Citation(s) in RCA: 207] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Indexed: 12/28/2022]
Abstract
Computational chemistry provides a versatile toolbox for studying mechanistic details of catalytic reactions and holds promise to deliver practical strategies to enable the rational in silico catalyst design. The versatile reactivity and nontrivial electronic structure effects, common for systems based on 3d transition metals, introduce additional complexity that may represent a particular challenge to the standard computational strategies. In this review, we discuss the challenges and capabilities of modern electronic structure methods for studying the reaction mechanisms promoted by 3d transition metal molecular catalysts. Particular focus will be placed on the ways of addressing the multiconfigurational problem in electronic structure calculations and the role of expert bias in the practical utilization of the available methods. The development of density functionals designed to address transition metals is also discussed. Special emphasis is placed on the methods that account for solvation effects and the multicomponent nature of practical catalytic systems. This is followed by an overview of recent computational studies addressing the mechanistic complexity of catalytic processes by molecular catalysts based on 3d metals. Cases that involve noninnocent ligands, multicomponent reaction systems, metal-ligand and metal-metal cooperativity, as well as modeling complex catalytic systems such as metal-organic frameworks are presented. Conventionally, computational studies on catalytic mechanisms are heavily dependent on the chemical intuition and expert input of the researcher. Recent developments in advanced automated methods for reaction path analysis hold promise for eliminating such human-bias from computational catalysis studies. A brief overview of these approaches is presented in the final section of the review. The paper is closed with general concluding remarks.
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Affiliation(s)
| | | | - Justin K. Kirkland
- Department
of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Jacob Townsend
- Department
of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Ali Hashemi
- Inorganic
Systems Engineering group, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Chong Liu
- Inorganic
Systems Engineering group, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Evgeny A. Pidko
- TheoMAT
group, ITMO University, Lomonosova 9, St. Petersburg 191002, Russia
- Inorganic
Systems Engineering group, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
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29
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Lesiuk M. Efficient singular‐value decomposition of the coupled‐cluster triple excitation amplitudes. J Comput Chem 2019; 40:1319-1332. [DOI: 10.1002/jcc.25788] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 01/06/2019] [Accepted: 01/08/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Michal Lesiuk
- Faculty of ChemistryUniversity of Warsaw Pasteura 1, 02‐093, Warsaw Poland
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30
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Hollett JW, Pegoretti N. On-top density functionals for the short-range dynamic correlation between electrons of opposite and parallel spin. J Chem Phys 2018; 148:164111. [DOI: 10.1063/1.5025171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Joshua W. Hollett
- Department of Chemistry, University of Winnipeg, Winnipeg, Manitoba, R3B 2G3, Canada
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
| | - Nicholas Pegoretti
- Department of Chemistry, University of Winnipeg, Winnipeg, Manitoba, R3B 2G3, Canada
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31
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Benavides-Riveros CL, Lathiotakis NN, Marques MAL. Towards a formal definition of static and dynamic electronic correlations. Phys Chem Chem Phys 2018; 19:12655-12664. [PMID: 28474027 DOI: 10.1039/c7cp01137g] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Some of the most spectacular failures of density-functional and Hartree-Fock theories are related to an incorrect description of the so-called static electron correlation. Motivated by recent progress in the N-representability problem of the one-body density matrix for pure states, we propose a method to quantify the static contribution to the electronic correlation. By studying several molecular systems we show that our proposal correlates well with our intuition of static and dynamic electron correlation. Our results bring out the paramount importance of the occupancy of the highest occupied natural spin-orbital in such quantification.
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32
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Ramos-Cordoba E, Salvador P, Matito E. Separation of dynamic and nondynamic correlation. Phys Chem Chem Phys 2018; 18:24015-23. [PMID: 27523386 DOI: 10.1039/c6cp03072f] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The account of electron correlation and its efficient separation into dynamic and nondynamic parts plays a key role in the development of computational methods. In this paper we suggest a physically-sound matrix formulation to split electron correlation into dynamic and nondynamic parts using the two-particle cumulant matrix and a measure of the deviation from idempotency of the first-order density matrix. These matrices are applied to a two-electron model, giving rise to a simplified electron correlation index that (i) depends only on natural orbitals and their occupancies, (ii) can be straightforwardly decomposed into orbital contributions and (iii) splits into dynamic and nondynamic correlation parts that (iv) admit a local version. These expressions are shown to account for dynamic and nondynamic correlation in a variety of systems containing different electron correlation regimes, thus providing the first separation of dynamic and nondynamic correlation using solely natural orbital occupancies.
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Affiliation(s)
- Eloy Ramos-Cordoba
- Faculty of Chemistry, University of the Basque Country UPV/EHU, and Donostia International Physics Center (DIPC)., P.K. 1072, 20080 Donostia, Euskadi, Spain. and Department of Chemistry, University of California Berkeley, Berkeley, California 94720, USA
| | - Pedro Salvador
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, University of Girona, 17071 Girona, Catalonia, Spain
| | - Eduard Matito
- Faculty of Chemistry, University of the Basque Country UPV/EHU, and Donostia International Physics Center (DIPC)., P.K. 1072, 20080 Donostia, Euskadi, Spain. and IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
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33
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Suchan J, Hollas D, Curchod BFE, Slavíček P. On the importance of initial conditions for excited-state dynamics. Faraday Discuss 2018; 212:307-330. [DOI: 10.1039/c8fd00088c] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The vast majority of ab initio excited-state simulations are performed within semiclassical, trajectory-based approaches. Apart from the underlying electronic-structure theory, the reliability of the simulations is controlled by a selection of initial conditions for the classical trajectories. We discuss appropriate choices of initial conditions for simulations of different experimental arrangements: dynamics initiated by continuum-wave (CW) laser fields or triggered by ultrashort laser pulses.
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Affiliation(s)
- Jiří Suchan
- Department of Physical Chemistry
- University of Chemistry and Technology, Prague
- 16628 Prague
- Czech Republic
| | - Daniel Hollas
- Department of Physical Chemistry
- University of Chemistry and Technology, Prague
- 16628 Prague
- Czech Republic
| | | | - Petr Slavíček
- Department of Physical Chemistry
- University of Chemistry and Technology, Prague
- 16628 Prague
- Czech Republic
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34
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Pérez-Guardiola A, Sandoval-Salinas ME, Casanova D, San-Fabián E, Pérez-Jiménez AJ, Sancho-García JC. The role of topology in organic molecules: origin and comparison of the radical character in linear and cyclic oligoacenes and related oligomers. Phys Chem Chem Phys 2018; 20:7112-7124. [DOI: 10.1039/c8cp00135a] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We discuss the nature of electron-correlation effects in carbon nanorings and nanobelts by a combined approach based on FT-DFT and RAS-SF methods.
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Affiliation(s)
- A. Pérez-Guardiola
- Department of Physical Chemistry
- University of Alicante
- E-03080 Alicante
- Spain
| | - M. E. Sandoval-Salinas
- Departament de Ciéncia de Materials i Química Física
- Institut de Química Teòrica i Computacional (IQTCUB)
- Universitat de Barcelona
- E-08028 Barcelona
- Spain
| | - D. Casanova
- Kimika Fakultatea
- Euskal Herriko Unibertsitatea (UPV/EHU) and Donostia International Physics Center (DIPC)
- E-20018 Donostia
- Spain
- IKERBASQUE
| | - E. San-Fabián
- Department of Physical Chemistry
- University of Alicante
- E-03080 Alicante
- Spain
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35
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Hollett JW, Li W. The Relative Alignment of Electron Momenta in Atoms and Molecules and the Effect of a Static Electric Field. J Phys Chem A 2017; 121:8026-8031. [DOI: 10.1021/acs.jpca.7b09439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Joshua W. Hollett
- Department
of Chemistry, University of Winnipeg, Winnipeg, Manitoba R3B 2G3, Canada
- Department
of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Wen Li
- Department
of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
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36
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Kjønstad EF, Koch H. Resolving the Notorious Case of Conical Intersections for Coupled Cluster Dynamics. J Phys Chem Lett 2017; 8:4801-4807. [PMID: 28927266 DOI: 10.1021/acs.jpclett.7b02118] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The motion of electrons and nuclei in photochemical events often involves conical intersections, or degeneracies between electronic states. They serve as funnels in nuclear relaxation processes where the electrons and nuclei couple nonadiabatically. Accurate ab initio quantum chemical models are essential for interpreting experimental measurements of such phenomena. In this Letter, we resolve a long-standing problem in coupled cluster theory, presenting the first formulation of the theory that correctly describes conical intersections between excited electronic states of the same symmetry. This new development demonstrates that the highly accurate coupled cluster theory can be applied to describe dynamics on excited electronic states involving conical intersections.
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Affiliation(s)
- Eirik F Kjønstad
- Department of Chemistry, Norwegian University of Science and Technology , 7491 Trondheim, Norway
- Department of Chemistry and the PULSE Institute, Stanford University , Stanford, California 94305, United States
| | - Henrik Koch
- Department of Chemistry, Norwegian University of Science and Technology , 7491 Trondheim, Norway
- Department of Chemistry and the PULSE Institute, Stanford University , Stanford, California 94305, United States
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37
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Sánchez HR. Revisiting the thermochemistry of chlorine fluorides. J Comput Chem 2017; 38:1930-1940. [PMID: 28608507 DOI: 10.1002/jcc.24838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 04/28/2017] [Accepted: 05/03/2017] [Indexed: 02/01/2023]
Abstract
In this work, accurate calculations of standard enthalpies of formation of chlorine fluorides (ClFn, n = 1-7; Cl2 F and Cl3 F2 ) were performed through the isodesmic reactions scheme. It is argued that, for many chlorine fluorides, the gold standard method of quantum chemistry (CCSD(T)) is not capable to predict enthalpy values nearing chemical accuracy if atomization scheme is used. This is underpinned by a thorough analysis of total atomization energy results and the inspection of multireference features of these compounds. Other thermodynamic quantities were also calculated at different temperatures. To complement the energetic description, elimination curves were studied through density functional theory as a computationally affordable alternative to highly correlated wave function-based methods. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Hernán R Sánchez
- Departamento de Química (Universidad Nacional de La Plata), Instituto de Física de Líquidos y Sistemas Biológicos (IFLySIB), Universidad Nacional de La Plata - CONICET, Calle 59 no. 789, La Plata, 1900, Argentina
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38
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Ashcroft NW. From Electrons and Nuclei to Assemblies of Correlated Atoms. Angew Chem Int Ed Engl 2017; 56:10224-10227. [PMID: 28654170 DOI: 10.1002/anie.201702671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Indexed: 11/07/2022]
Abstract
What constitutes an atom? The answer may depend on whether you ask a physicist or a chemist. But the complementary views lead to productive overlap in atomic theory. Limiting cases, under high pressures and temperatures, have had a profound impact in a wider context.
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Affiliation(s)
- Neil W Ashcroft
- Laboratory of Atomic and Solid State Physics, Cornell University, Clark Hall, Ithaca, NY, 14853, USA
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Affiliation(s)
- Neil W. Ashcroft
- Laboratory of Atomic and Solid State Physics; Cornell University; Clark Hall Ithaca NY 14853 USA
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40
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Ramos-Cordoba E, Matito E. Local Descriptors of Dynamic and Nondynamic Correlation. J Chem Theory Comput 2017; 13:2705-2711. [DOI: 10.1021/acs.jctc.7b00293] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eloy Ramos-Cordoba
- Kimika
Fakultatea, Euskal Herriko Unibertsitatea, UPV/EHU, and Donostia International Physics Center (DIPC), P.K. 1072, 20080 Donostia, Euskadi Spain
| | - Eduard Matito
- Kimika
Fakultatea, Euskal Herriko Unibertsitatea, UPV/EHU, and Donostia International Physics Center (DIPC), P.K. 1072, 20080 Donostia, Euskadi Spain
- IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
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41
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Mullinax JW, Sokolov AY, Schaefer HF. Can density cumulant functional theory describe static correlation effects? J Chem Theory Comput 2016; 11:2487-95. [PMID: 26575548 DOI: 10.1021/acs.jctc.5b00346] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We evaluate the performance of density cumulant functional theory (DCT) for capturing static correlation effects. In particular, we examine systems with significant multideterminant character of the electronic wave function, such as the beryllium dimer, diatomic carbon, m-benzyne, 2,6-pyridyne, twisted ethylene, as well as the barrier for double-bond migration in cyclobutadiene. We compute molecular properties of these systems using the ODC-12 and DC-12 variants of DCT and compare these results to multireference configuration interaction and multireference coupled-cluster theories, as well as single-reference coupled-cluster theory with single, double (CCSD), and perturbative triple excitations [CCSD(T)]. For all systems the DCT methods show intermediate performance between that of CCSD and CCSD(T), with significant improvement over the former method. In particular, for the beryllium dimer, m-benzyne, and 2,6-pyridyne, the ODC-12 method along with CCSD(T) correctly predict the global minimum structures, while CCSD predictions fail qualitatively, underestimating the multireference effects. Our results suggest that the DC-12 and ODC-12 methods are capable of describing emerging static correlation effects but should be used cautiously when highly accurate results are required. Conveniently, the appearance of multireference effects in DCT can be diagnosed by analyzing the DCT natural orbital occupations, which are readily available at the end of the energy computation.
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Affiliation(s)
- J Wayne Mullinax
- Center for Computational Quantum Chemistry, University of Georgia , Athens, Georgia 30602, United States
| | - Alexander Yu Sokolov
- Center for Computational Quantum Chemistry, University of Georgia , Athens, Georgia 30602, United States.,Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia , Athens, Georgia 30602, United States
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Odoh SO, Manni GL, Carlson RK, Truhlar DG, Gagliardi L. Separated-pair approximation and separated-pair pair-density functional theory. Chem Sci 2016; 7:2399-2413. [PMID: 29997782 PMCID: PMC6003605 DOI: 10.1039/c5sc03321g] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/11/2015] [Indexed: 11/23/2022] Open
Abstract
Multi-configuration pair-density functional theory (MC-PDFT) has proved to be a powerful way to combine the capabilities of multi-configuration self-consistent-field theory to represent the an electronic wave function with a highly efficient way to include dynamic correlation energy by density functional theory. All applications reported previously involved complete active space self-consistent-field (CASSCF) theory for the reference wave function. For treating large systems efficiently, it is necessary to ask whether good accuracy is retained when using less complete configuration interaction spaces. To answer this question, we present here calculations employing MC-PDFT with the separated pair (SP) approximation, which is a special case (defined in this article) of generalized active space self-consistent-field (GASSCF) theory in which no more than two orbitals are included in any GAS subspace and in which inter-subspace excitations are excluded. This special case of MC-PDFT will be called SP-PDFT. In SP-PDFT, the electronic kinetic energy and the classical Coulomb energy, the electronic density and its gradient, and the on-top pair density and its gradient are obtained from an SP approximation wave function; the electronic energy is then calculated from the first two of these quantities and an on-top density functional of the last four. The accuracy of the SP-PDFT method for predicting the structural properties and bond dissociation energies of twelve diatomic molecules and two triatomic molecules is compared to the SP approximation itself and to CASSCF, MC-PDFT based on CASSCF, CASSCF followed by second order perturbation theory (CASPT2), and Kohn-Sham density functional theory with the PBE exchange-correlation potential. We show that SP-PDFT reproduces the accuracy of MC-PDFT based on the corresponding CASSCF wave function for predicting C-H bond dissociation energies, the reaction barriers of pericyclic reactions and the properties of open-shell singlet systems, all at only a small fraction of the computational cost.
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Affiliation(s)
- Samuel O Odoh
- Department of Chemistry , Chemical Theory Center , Supercomputing Institute , University of Minnesota , 207 Pleasant Street SE , Minneapolis , MN 55455-0431 , USA . ;
| | - Giovanni Li Manni
- Department of Chemistry , Chemical Theory Center , Supercomputing Institute , University of Minnesota , 207 Pleasant Street SE , Minneapolis , MN 55455-0431 , USA . ;
- Max-Planck Institut für Festkörperforshung , Heisenbergstraße 1 , 70569 Stuttgart , Germany
| | - Rebecca K Carlson
- Department of Chemistry , Chemical Theory Center , Supercomputing Institute , University of Minnesota , 207 Pleasant Street SE , Minneapolis , MN 55455-0431 , USA . ;
| | - Donald G Truhlar
- Department of Chemistry , Chemical Theory Center , Supercomputing Institute , University of Minnesota , 207 Pleasant Street SE , Minneapolis , MN 55455-0431 , USA . ;
| | - Laura Gagliardi
- Department of Chemistry , Chemical Theory Center , Supercomputing Institute , University of Minnesota , 207 Pleasant Street SE , Minneapolis , MN 55455-0431 , USA . ;
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Ruzsinszky A, Zhang IY, Scheffler M. Insight into organic reactions from the direct random phase approximation and its corrections. J Chem Phys 2015; 143:144115. [DOI: 10.1063/1.4932306] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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Mezei PD, Csonka GI, Ruzsinszky A. Accurate Complete Basis Set Extrapolation of Direct Random Phase Correlation Energies. J Chem Theory Comput 2015; 11:3961-7. [DOI: 10.1021/acs.jctc.5b00269] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Pál D. Mezei
- Department
of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1521 Budapest, Hungary
| | - Gábor I. Csonka
- Department
of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1521 Budapest, Hungary
| | - Adrienn Ruzsinszky
- Department
of Physics, Temple University, Philadelphia, Pennsylvania 19122, United States
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Vogiatzis KD, Li Manni G, Stoneburner SJ, Ma D, Gagliardi L. Systematic Expansion of Active Spaces beyond the CASSCF Limit: A GASSCF/SplitGAS Benchmark Study. J Chem Theory Comput 2015; 11:3010-21. [DOI: 10.1021/acs.jctc.5b00191] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Konstantinos D. Vogiatzis
- Department
of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Giovanni Li Manni
- Department
of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
- Max Planck Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Samuel J. Stoneburner
- Department
of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Dongxia Ma
- Department
of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
- Max Planck Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Laura Gagliardi
- Department
of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
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Mezei PD, Csonka GI, Kállay M. Accurate Diels–Alder Reaction Energies from Efficient Density Functional Calculations. J Chem Theory Comput 2015; 11:2879-88. [DOI: 10.1021/acs.jctc.5b00223] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Pál D. Mezei
- Department of Inorganic and Analytical
Chemistry, Budapest University of Technology and Economics, H-1521 Budapest, Hungary
| | - Gábor I. Csonka
- Department of Inorganic and Analytical
Chemistry, Budapest University of Technology and Economics, H-1521 Budapest, Hungary
| | - Mihály Kállay
- MTA-BME Lendület
Quantum Chemistry Research Group, Department of Physical Chemistry
and Materials Science, Budapest University of Technology and Economics, H-1521 Budapest, P.O. Box 91, Hungary
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Sayres SG, Hosler ER, Leone SR. Exposing the Role of Electron Correlation in Strong-Field Double Ionization: X-ray Transient Absorption of Orbital Alignment in Xe+ and Xe2+. J Phys Chem A 2014; 118:8614-24. [DOI: 10.1021/jp503468u] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Scott G. Sayres
- Departments
of Chemistry
and Physics, University of California at Berkeley, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Erik R. Hosler
- Departments
of Chemistry
and Physics, University of California at Berkeley, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Stephen R. Leone
- Departments
of Chemistry
and Physics, University of California at Berkeley, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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Ramabhadran RO, Raghavachari K. Extrapolation to the Gold-Standard in Quantum Chemistry: Computationally Efficient and Accurate CCSD(T) Energies for Large Molecules Using an Automated Thermochemical Hierarchy. J Chem Theory Comput 2013; 9:3986-94. [PMID: 26592394 DOI: 10.1021/ct400465q] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The CCSD(T) method is known as the gold-standard in quantum chemistry and has been the method of choice in quantum chemistry for over 20 years to obtain accurate bond energies and molecular properties. Its computational cost formally scales as the seventh power of the size of the system and can be prohibitive for large molecules. As part of our efforts to reduce the computational cost of the CCSD(T) method yet retain its accuracy, we present a simple, efficient, and user-friendly protocol to extrapolate to CCSD(T) energies in conjunction with MP2 energies. The method is based on the automated error-canceling thermochemical hierarchy previously developed by us called the Connectivity-Based Hierarchy (CBH). For a test set containing 30 diverse nonaromatic organic molecules and biomonomers, we obtain highly accurate extrapolated CCSD(T) energies (with a mean absolute error of only 0.2-0.3 kcal/mol with different basis-set). Additionally, the work also features the successful extrapolation to CCSD energies using a similar protocol.
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Affiliation(s)
| | - Krishnan Raghavachari
- Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States
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Harvey JN. Spin-forbidden reactions: computational insight into mechanisms and kinetics. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2013. [DOI: 10.1002/wcms.1154] [Citation(s) in RCA: 163] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Jeremy N. Harvey
- School of Chemistry and Centre for Computational Chemistry; University of Bristol, Cantock's Close; Bristol United Kingdom
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