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Li S, Misiewicz JP, Evangelista FA. Intruder-free cumulant-truncated driven similarity renormalization group second-order multireference perturbation theory. J Chem Phys 2023; 159:114106. [PMID: 37712785 DOI: 10.1063/5.0159403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 08/14/2023] [Indexed: 09/16/2023] Open
Abstract
Accurate multireference electronic structure calculations are important for constructing potential energy surfaces. Still, even in the case of low-scaling methods, their routine use is limited by the steep growth of the computational and storage costs as the active space grows. This is primarily due to the occurrence of three- and higher-body density matrices or, equivalently, their cumulants. This work examines the effect of various cumulant truncation schemes on the accuracy of the driven similarity renormalization group second-order multireference perturbation theory. We test four different levels of three-body reduced density cumulant truncations that set different classes of cumulant elements to zero. Our test cases include the singlet-triplet gap of CH2, the potential energy curves of the XΣg+1 and AΣu+3 states of N2, and the singlet-triplet splittings of oligoacenes. Our results show that both relative and absolute errors introduced by these cumulant truncations can be as small as 0.5 kcal mol-1 or less. At the same time, the amount of memory required is reduced from O(NA6) to O(NA5), where NA is the number of active orbitals. No additional regularization is needed to prevent the intruder state problem in the cumulant-truncated second-order driven similarity renormalization group multireference perturbation theory methods.
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Affiliation(s)
- Shuhang Li
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Jonathon P Misiewicz
- 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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2
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Reiter S, Bäuml L, Hauer J, de Vivie-Riedle R. Q-Band relaxation in chlorophyll: new insights from multireference quantum dynamics. Phys Chem Chem Phys 2022; 24:27212-27223. [DOI: 10.1039/d2cp02914f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The ultrafast relaxation within the Q-bands of chlorophyll plays a crucial role in photosynthetic light-harvesting. We investigate this process via nuclear and electronic quantum dynamics on multireference potential energy surfaces.
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Affiliation(s)
- Sebastian Reiter
- Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstr. 11, 81377 Munich, Germany
| | - Lena Bäuml
- Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstr. 11, 81377 Munich, Germany
| | - Jürgen Hauer
- Department of Chemistry, Technical University of Munich, Lichtenbergstr. 4, 85747 Garching, Germany
| | - Regina de Vivie-Riedle
- Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstr. 11, 81377 Munich, Germany
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3
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Hapka M, Przybytek M, Pernal K. Symmetry-Adapted Perturbation Theory Based on Multiconfigurational Wave Function Description of Monomers. J Chem Theory Comput 2021; 17:5538-5555. [PMID: 34517707 PMCID: PMC8444344 DOI: 10.1021/acs.jctc.1c00344] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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We present a formulation
of the multiconfigurational (MC) wave
function symmetry-adapted perturbation theory (SAPT). The method is
applicable to noncovalent interactions between monomers which require
a multiconfigurational description, in particular when the interacting
system is strongly correlated or in an electronically excited state.
SAPT(MC) is based on one- and two-particle reduced density matrices
of the monomers and assumes the single-exchange approximation for
the exchange energy contributions. Second-order terms are expressed
through response properties from extended random phase approximation
(ERPA). The dispersion components of SAPT(MC) have been introduced
in our previous works [HapkaM.2019, 15, 1016−102730525591; HapkaM.2019, 15, 6712–672331670950]. SAPT(MC) is applied either with generalized valence
bond perfect pairing (GVB) or with complete active space self-consistent
field (CASSCF) treatment of the monomers. We discuss two model multireference
systems: the H2 ··· H2 dimer
in out-of-equilibrium geometries and interaction between the argon
atom and excited state of ethylene. Using the C2H4* ··· Ar complex as an example, we examine second-order
terms arising from negative transitions in the linear response function
of an excited monomer. We demonstrate that the negative-transition
terms must be accounted for to ensure qualitative prediction of induction
and dispersion energies and develop a procedure allowing for their
computation. Factors limiting the accuracy of SAPT(MC) are discussed
in comparison with other second-order SAPT schemes on a data set of
small single-reference dimers.
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Affiliation(s)
- Michał Hapka
- Institute of Physics, Lodz University of Technology, ul. Wolczanska 219, 90-924 Lodz, Poland.,Faculty of Chemistry, University of Warsaw, ul. L. Pasteura 1, 02-093 Warsaw, Poland
| | - Michał Przybytek
- Faculty of Chemistry, University of Warsaw, ul. L. Pasteura 1, 02-093 Warsaw, Poland
| | - Katarzyna Pernal
- Institute of Physics, Lodz University of Technology, ul. Wolczanska 219, 90-924 Lodz, Poland
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Chaudhuri RK, Chattopadhyay S. Description of the Methylene Amidogene Radical and Its Anion with an Economical Treatment of Correlation Effects Using Density Functional Theory Orbitals. J Phys Chem A 2021; 125:543-558. [PMID: 33417452 DOI: 10.1021/acs.jpca.0c08635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ground and low-lying excited state electronic structural properties (such as equilibrium geometries, harmonic frequencies, excitation energies, barrier energy, and so on) of the methylene amidogene radical (H2CN) and its anion (H2CN-) have been studied using the CASCI (complete active space configuration interaction) and SSMRPT (state-specific multireference Møller-Plesset perturbation theory) methods with density function theory (DFT) orbitals. Here, the span of the active orbitals have been obtained from Kohn-Sham DFT using B3LYP exchange-correlation functionals in the CASCI (DFT-CASCI) approximation to describe nondynamic correlation associated with electronic degeneracies. The DFT-SSMRPT protocol provides an attractive way to deal with both dynamical and nondynamical correlation effects in strongly correlated systems such as H2CN and H2CN-. The present work clearly indicates that the electronic absorption band near 35,050 cm-1 corresponds to the B̃2A1 ← X̃2B2 transition. DFT-SSMRPT findings are in close agreement with high-level theoretical estimates. It is concluded that the transition at 1725 cm-1 could be due to the CN stretching of the trans-HCNH isomer which is originally assigned to the CN stretch of H2CN in the experiment. The present results confirm most of the previous vibrational assignments. It is not possible to definitively assign a transition to the 35,600 cm-1 band with the present estimations, suggesting further experiment is urgently called for.
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Affiliation(s)
| | - Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
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5
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Chattopadhyay S. Single-Root Multireference Brillouin-Wigner Perturbative Approach to Excitation Energies. ACS OMEGA 2021; 6:1668-1686. [PMID: 33490826 PMCID: PMC7818614 DOI: 10.1021/acsomega.0c05714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 12/28/2020] [Indexed: 06/12/2023]
Abstract
The state-specific Brillouin-Wigner multireference perturbation theory [which employs Jeziorski-Monkhorst parametrization of the wave function] using improved virtual orbitals, denoted as IVO-BWMRPT, is applied to calculate excitation energies (EEs) for methylene, ethylene, trimethylenemethane, and benzyne systems exhibiting various degrees of diradical character. In IVO-BWMRPT, all of the parameters appearing in the wave function ansatz are optimized for a specific electronic state. For these systems, the IVO-BWMRPT method provides EEs that are in close agreement with the benchmark results and experiments, where available, indicating that the method does not introduce imbalance in the target-specific treatment of closed- and open-shell states involved. The good performance of the present methodology is primarily related to structural compactness of the formalism. Overall, present findings are encouraging for both further development of the approach and chemical applications on the energy differences of strongly correlated systems.
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Affiliation(s)
- Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology,
Shibpur, Howrah 711103, India
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Bhagat V, Schumann J, Bettinger HF. Unusual Nitrene Oxidation Product Formation by Metathesis Involving the Dioxygen O-O and Borylnitrene B-N Bonds. Chemistry 2020; 26:12654-12663. [PMID: 32902001 PMCID: PMC7590100 DOI: 10.1002/chem.202002445] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/11/2020] [Indexed: 01/08/2023]
Abstract
The reaction of dioxygen with nitrenes can have significant energy barriers, although both reactants are triplet diradicals and the formation of nitroso-O-oxides is spin-allowed. By means of matrix-isolation infrared spectroscopy in solid argon, nitrogen, and neon, and through high-level computational quantum chemistry, it is shown herein that a 3-nitreno-1,3,2-benzodioxaborole CatBN (Cat=catecholato) reacts with dioxygen under cryogenic conditions thermally at temperatures as low as 7 K to produce two distinct products, an anti-nitroso-O-oxide and a nitritoborane CatBONO. The computed barriers for the formation of nitroso-O-oxide isomers are very low. Whereas anti-nitroso-O-oxide is kinetically trapped, its bisected isomer has a very low barrier for metathesis, yielding the CatBO+NO radicals in a strongly exothermic reaction; these radicals can combine under matrix-isolation conditions to give nitritoborane CatBONO. The trapped isomer, anti-nitroso-O-oxide, can form the nitritoborane CatBONO only after photoexcitation, possibly involving isomerization to the bisected isomer of anti-nitroso-O-oxide.
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Affiliation(s)
- Virinder Bhagat
- Institut für Organische ChemieUniversität TübingenAuf der Morgenstelle 1872076TübingenGermany
| | - Julia Schumann
- Institut für Organische ChemieUniversität TübingenAuf der Morgenstelle 1872076TübingenGermany
| | - Holger F. Bettinger
- Institut für Organische ChemieUniversität TübingenAuf der Morgenstelle 1872076TübingenGermany
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Manna S, Chaudhuri RK, Chattopadhyay S. Taming the excited states of butadiene, hexatriene, and octatetraene using state specific multireference perturbation theory with density functional theory orbitals. J Chem Phys 2020; 152:244105. [DOI: 10.1063/5.0007198] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Shovan Manna
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
| | | | - Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
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8
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Manna S, Sinha Ray S, Ghosh P, Chattopadhyay S. Structural properties and isomerisation of simple S-nitrosothiols: ab initio studies with a simplified treatment of correlation effects. Mol Phys 2020. [DOI: 10.1080/00268976.2019.1641639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Shovan Manna
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Howrah, India
| | | | - Pradipta Ghosh
- Department of Chemistry, Jhargram Raj College, Jhargram, India
| | - Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Howrah, India
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9
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Chattopadhyay S. Investigation of Multiple-Bond Dissociation Using Brillouin–Wigner Perturbation with Improved Virtual Orbitals. J Phys Chem A 2020; 124:1444-1463. [DOI: 10.1021/acs.jpca.9b11522] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
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10
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Manna S, Ray SS, Chattopadhyay S, Chaudhuri RK. A simplified account of the correlation effects to bond breaking processes: The Brillouin-Wigner perturbation theory using a multireference formulation. J Chem Phys 2019. [DOI: 10.1063/1.5097657] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Shovan Manna
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
| | - Suvonil Sinha Ray
- Department of Chemistry, University of Calcutta, Kolkata 700009, India
| | - Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah 711103, India
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11
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Chattopadhyay S. Ab Initio Probing of the Ground State of Tetraradicals: Breakdown of Hund's Multiplicity Rule. J Phys Chem A 2019; 123:2211-2226. [PMID: 30794415 DOI: 10.1021/acs.jpca.8b10514] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electronic structure of organic σ-type polyradical including 2,4,6-tridehydropyridine radical cation (246-TDHP) and three isomers of tetradehydrobenzene (TDHB) have been studied using a computationally robust and cost-effective second-order multireference perturbative model which provides a balanced treatment of nondynamic and dynamic contributions to the electron correlation problem in the ground or excited electronic states which are imperative for predicting structural properties (e.g., ground state multiplicity, energy gaps between high-spin and low-spin states, etc.) of polyradicals. Energy gaps are useful to capture insight into the degree of interaction between the radical sites. An important finding of this study is that the tetraradicals considered here possess singlet ground states, contrary to Hund's rule. Present findings are in close agreement with the available high-level ab initio estimates at attainable cost implying that a perturbative description of the systems is adequate. The impact of N+ on the nature of ground state for the 246-TDHP have also analyzed. The singlet-triplet energy gaps for 1245- and 1234-TDHB are smaller than for o-benzyne mainly due to the ring strain. 1235-TDHB is 14.42 and 11.05 kcal/mol lower in energy than 1245- and 1234-isomers, respectively. IVO-SSMRPT predicts 1A1-3B2 and 1A1-5B2 gaps of 25.84 and 105.15 kcal/mol, respectively for the 246-TDHP cation.
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Affiliation(s)
- Sudip Chattopadhyay
- Department of Chemistry , Indian Institute of Engineering Science and Technology , Shibpur , Howrah 711103 , India
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12
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Miranda U. Long-range interactions and the role of static and dynamic correlation energy in scandium dimer. Mol Phys 2019. [DOI: 10.1080/00268976.2018.1519199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Ulises Miranda
- Institute of Atomic Physics and Spectroscopy, University of Latvia, Riga, Latvia
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13
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Smart SE, Scrape PG, Butler LJ, Mazziotti DA. Using reduced density matrix techniques to capture static and dynamic correlation in the energy landscape for the decomposition of the CH2CH2ONO radical and support a non-IRC pathway. J Chem Phys 2018; 149:024302. [DOI: 10.1063/1.5024512] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Scott E. Smart
- The James Franck Institute and Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA
| | - Preston G. Scrape
- The James Franck Institute and Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA
| | - Laurie J. Butler
- The James Franck Institute and Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA
| | - David A. Mazziotti
- The James Franck Institute and Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA
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14
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Patkowski K, Żuchowski PS, Smith DGA. First-order symmetry-adapted perturbation theory for multiplet splittings. J Chem Phys 2018; 148:164110. [PMID: 29716224 DOI: 10.1063/1.5021891] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a symmetry-adapted perturbation theory (SAPT) for the interaction of two high-spin open-shell molecules (described by their restricted open-shell Hartree-Fock determinants) resulting in low-spin states of the complex. The previously available SAPT formalisms, except for some system-specific studies for few-electron complexes, were restricted to the high-spin state of the interacting system. Thus, the new approach provides, for the first time, a SAPT-based estimate of the splittings between different spin states of the complex. We have derived and implemented the lowest-order SAPT term responsible for these splittings, that is, the first-order exchange energy. We show that within the so-called S2 approximation commonly used in SAPT (neglecting effects that vanish as fourth or higher powers of intermolecular overlap integrals), the first-order exchange energies for all multiplets are linear combinations of two matrix elements: a diagonal exchange term that determines the spin-averaged effect and a spin-flip term responsible for the splittings between the states. The numerical factors in this linear combination are determined solely by the Clebsch-Gordan coefficients: accordingly, the S2 approximation implies a Heisenberg Hamiltonian picture with a single coupling strength parameter determining all the splittings. The new approach is cast into both molecular-orbital and atomic-orbital expressions: the latter enable an efficient density-fitted implementation. We test the newly developed formalism on several open-shell complexes ranging from diatomic systems (Li⋯H, Mn⋯Mn, …) to the phenalenyl dimer.
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Affiliation(s)
- Konrad Patkowski
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, USA
| | - Piotr S Żuchowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, Torun 87-100, Poland
| | - Daniel G A Smith
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, USA
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15
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Ashley DC, Jakubikova E. Ironing out the photochemical and spin-crossover behavior of Fe(II) coordination compounds with computational chemistry. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.02.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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16
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Ghosh A, Sinha Ray S, Chaudhuri RK, Chattopadhyay S. Four-Component Relativistic State-Specific Multireference Perturbation Theory with a Simplified Treatment of Static Correlation. J Phys Chem A 2017; 121:1487-1501. [PMID: 28112937 DOI: 10.1021/acs.jpca.6b11348] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The relativistic multireference (MR) perturbative approach is one of the most successful tools for the description of computationally demanding molecular systems of heavy elements. We present here the ground state dissociation energy surfaces, equilibrium bond lengths, harmonic frequencies, and dissociation energies of Ag2, Cu2, Au2, and I2 computed using the four-component (4c) relativistic spinors based state-specific MR perturbation theory (SSMRPT) with improved virtual orbital complete active space configuration interaction (IVO-CASCI) functions. The IVO-CASCI method is a simple, robust, useful and lower cost alternative to the complete active space self-consistent field approach for treating quasidegenerate situations. The redeeming features of the resulting method, termed as 4c-IVO-SSMRPT, lies in (i) manifestly size-extensivity, (ii) exemption from intruder problems, (iii) the freedom of convenient multipartitionings of the Hamiltonian, (iv) flexibility of the relaxed and unrelaxed descriptions of the reference coefficients, and (v) manageable cost/accuracy ratio. The present method delivers accurate descriptions of dissociation processes of heavy element systems. Close agreement with reference values has been found for the calculated molecular constants indicating that our 4c-IVOSSMRPT provides a robust and economic protocol for determining the structural properties for the ground state of heavy element molecules with eloquent MR character as it treats correlation and relativity on equal footing.
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Affiliation(s)
- Anirban Ghosh
- Department of Chemistry, Indian Institute of Engineering Science and Technology , Shibpur, Howrah 711103, India
| | - Suvonil Sinha Ray
- Department of Chemistry, Indian Institute of Engineering Science and Technology , Shibpur, Howrah 711103, India
| | - Rajat K Chaudhuri
- Theoretical Physics, Indian Institute of Astrophysics , Bangalore 560034, India
| | - Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology , Shibpur, Howrah 711103, India
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17
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Hannon KP, Li C, Evangelista FA. An integral-factorized implementation of the driven similarity renormalization group second-order multireference perturbation theory. J Chem Phys 2017; 144:204111. [PMID: 27250283 DOI: 10.1063/1.4951684] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We report an efficient implementation of a second-order multireference perturbation theory based on the driven similarity renormalization group (DSRG-MRPT2) [C. Li and F. A. Evangelista, J. Chem. Theory Comput. 11, 2097 (2015)]. Our implementation employs factorized two-electron integrals to avoid storage of large four-index intermediates. It also exploits the block structure of the reference density matrices to reduce the computational cost to that of second-order Møller-Plesset perturbation theory. Our new DSRG-MRPT2 implementation is benchmarked on ten naphthyne isomers using basis sets up to quintuple-ζ quality. We find that the singlet-triplet splittings (ΔST) of the naphthyne isomers strongly depend on the equilibrium structures. For a consistent set of geometries, the ΔST values predicted by the DSRG-MRPT2 are in good agreements with those computed by the reduced multireference coupled cluster theory with singles, doubles, and perturbative triples.
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Affiliation(s)
- Kevin P Hannon
- Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Chenyang Li
- 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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18
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Li C, Evangelista FA. Towards numerically robust multireference theories: The driven similarity renormalization group truncated to one- and two-body operators. J Chem Phys 2017; 144:164114. [PMID: 27131538 DOI: 10.1063/1.4947218] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The first nonperturbative version of the multireference driven similarity renormalization group (MR-DSRG) theory [C. Li and F. A. Evangelista, J. Chem. Theory Comput. 11, 2097 (2015)] is introduced. The renormalization group structure of the MR-DSRG equations ensures numerical robustness and avoidance of the intruder-state problem, while the connected nature of the amplitude and energy equations guarantees size consistency and extensivity. We approximate the MR-DSRG equations by keeping only one- and two-body operators and using a linearized recursive commutator approximation of the Baker-Campbell-Hausdorff expansion [T. Yanai and G. K.-L. Chan, J. Chem. Phys. 124, 194106 (2006)]. The resulting linearized MR-DSRG scheme with one- and two-body operators [MR-LDSRG(2)] contains only 39 terms and scales as O(N(2)NP (2)NH (2)) where NH, NP, and N correspond to the number of hole, particle, and total orbitals, respectively. Benchmark MR-LDSRG(2) computations on the hydrogen fluoride and molecular nitrogen binding curves and the singlet-triplet splitting of p-benzyne yield results comparable in accuracy to those from multireference configuration interaction, Mukherjee multireference coupled cluster theory, and internally contracted multireference coupled cluster theory.
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Affiliation(s)
- Chenyang Li
- 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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19
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Chattopadhyay S, Chaudhuri RK, Mahapatra US, Ghosh A, Ray SS. State-specific multireference perturbation theory: development and present status. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2016. [DOI: 10.1002/wcms.1248] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Sudip Chattopadhyay
- Department of Chemistry; Indian Institute of Engineering Science and Technology; Shibpur, Howrah India
| | | | | | - Anirban Ghosh
- Department of Chemistry; Indian Institute of Engineering Science and Technology; Shibpur, Howrah India
| | - Suvonil Sinha Ray
- Department of Chemistry; Indian Institute of Engineering Science and Technology; Shibpur, Howrah India
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20
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Kaplan IG, Miranda U. Multi-reference Ab initio calculations of 3d transition-metal dimers: Sc2. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2014. [DOI: 10.1134/s0036024414110089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Angeli C, Cimiraglia R. Some Useful Odds and Ends From the n-Electron Valence State Perturbation Theory. J Phys Chem A 2014; 118:6435-9. [DOI: 10.1021/jp5019263] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Celestino Angeli
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
| | - Renzo Cimiraglia
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17, 44121 Ferrara, Italy
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Kalemos A, Mavridis A. All electron ab initio calculations on the ScTi molecule: a really hard nut to crack. Theor Chem Acc 2013. [DOI: 10.1007/s00214-013-1408-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Schapiro I, Sivalingam K, Neese F. Assessment of n-Electron Valence State Perturbation Theory for Vertical Excitation Energies. J Chem Theory Comput 2013; 9:3567-80. [DOI: 10.1021/ct400136y] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Igor Schapiro
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim an
der Ruhr, Germany
| | - Kantharuban Sivalingam
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim an
der Ruhr, Germany
| | - Frank Neese
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim an
der Ruhr, Germany
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Chang SW, Witek HA. Choice of Optimal Shift Parameter for the Intruder State Removal Techniques in Multireference Perturbation Theory. J Chem Theory Comput 2012; 8:4053-61. [DOI: 10.1021/ct2006924] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shu-Wei Chang
- Department of Applied Chemistry and Institute of Molecular
Science, National Chiao Tung University, Hsinchu, Taiwan
| | - Henryk A. Witek
- Department of Applied Chemistry and Institute of Molecular
Science, National Chiao Tung University, Hsinchu, Taiwan
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25
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State specific multireference Møller–Plesset perturbation theory: A few applications to ground, excited and ionized states. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2011.04.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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26
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State-specific complete active space multireference Møller–Plesset perturbation approach for multireference situations: illustrating the bond breaking in hydrogen halides. Theor Chem Acc 2012. [DOI: 10.1007/s00214-012-1213-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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27
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Viegas LP, Varandas AJC. A detailed test study of barrier heights for the HO2 + H2O + O3 reaction with various forms of multireference perturbation theory. J Chem Phys 2012; 136:114312. [DOI: 10.1063/1.3695371] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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28
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Atanasov M, Ganyushin D, Pantazis DA, Sivalingam K, Neese F. Detailed ab initio first-principles study of the magnetic anisotropy in a family of trigonal pyramidal iron(II) pyrrolide complexes. Inorg Chem 2011; 50:7460-77. [PMID: 21744845 DOI: 10.1021/ic200196k] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A theoretical, computational, and conceptual framework for the interpretation and prediction of the magnetic anisotropy of transition metal complexes with orbitally degenerate or orbitally nearly degenerate ground states is explored. The treatment is based on complete active space self-consistent field (CASSCF) wave functions in conjunction with N-electron valence perturbation theory (NEVPT2) and quasidegenerate perturbation theory (QDPT) for treatment of magnetic field- and spin-dependent relativistic effects. The methodology is applied to a series of Fe(II) complexes in ligand fields of almost trigonal pyramidal symmetry as provided by several variants of the tris-pyrrolylmethyl amine ligand (tpa). These systems have recently attracted much attention as mononuclear single-molecule magnet (SMM) complexes. This study aims to establish how the ligand field can be fine tuned in order to maximize the magnetic anisotropy barrier. In trigonal ligand fields high-spin Fe(II) complexes adopt an orbitally degenerate (5)E ground state with strong in-state spin-orbit coupling (SOC). We study the competing effects of SOC and the (5)E⊗ε multimode Jahn-Teller effect as a function of the peripheral substituents on the tpa ligand. These subtle distortions were found to have a significant effect on the magnetic anisotropy. Using a rigorous treatment of all spin multiplets arising from the triplet and quintet states in the d(6) configuration the parameters of the effective spin-Hamiltonian (SH) approach were predicted from first principles. Being based on a nonperturbative approach we investigate under which conditions the SH approach is valid and what terms need to be retained. It is demonstrated that already tiny geometric distortions observed in the crystal structures of four structurally and magnetically well-documented systems, reported recently, i.e., [Fe(tpa(R))](-) (R = tert-butyl, Tbu (1), mesityl, Mes (2), phenyl, Ph (3), and 2,6-difluorophenyl, Dfp (4), are enough to lead to five lowest and thermally accessible spin sublevels described sufficiently well by S = 2 SH provided that it is extended with one fourth order anisotropy term. Using this most elementary parametrization that is consistent with the actual physics, the reported magnetization data for the target systems were reinterpreted and found to be in good agreement with the ab initio results. The multiplet energies from the ab initio calculations have been fitted with remarkable consistency using a ligand field (angular overlap) model (ab initio ligand field, AILFT). This allows for determination of bonding parameters and quantitatively demonstrates the correlation between increasingly negative D values and changes in the σ-bond strength induced by the peripheral ligands. In fact, the sigma-bonding capacity (and hence the Lewis basicity) of the ligand decreases along the series 1 > 2 > 3 > 4.
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Affiliation(s)
- Mihail Atanasov
- Institute for Physical and Theoretical Chemistry, University of Bonn, Wegelerstrasse 12, D-53115 Bonn, Germany.
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29
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Granovsky AA. Extended multi-configuration quasi-degenerate perturbation theory: The new approach to multi-state multi-reference perturbation theory. J Chem Phys 2011; 134:214113. [DOI: 10.1063/1.3596699] [Citation(s) in RCA: 519] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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30
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Andrzejak M, Witek HA. The elusive excited states of bithiophene: a CASPT2 detective story. Theor Chem Acc 2011. [DOI: 10.1007/s00214-011-0916-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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31
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Camacho C, Cimiraglia R, Witek HA. Reply to the ‘Comment on “Multiconfigurational perturbation theory can predict a false ground state”’ by J. Soto, F. Avila, J. C. Otero and J. F. Arenas, Phys. Chem. Chem. Phys., 2011, DOI: 10.1039/C0CP01917H. Phys Chem Chem Phys 2011. [DOI: 10.1039/c1cp20177h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Soto J, Avila FJ, Otero JC, Arenas JF. Comment on “Multiconfigurational perturbation theory can predict a false ground state” by C. Camacho, R. Cimiraglia and H. A. Witek, Phys. Chem. Chem. Phys., 2010, 12, 5058. Phys Chem Chem Phys 2011; 13:7230-1; author reply 7232-3. [DOI: 10.1039/c0cp01917h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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33
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A Modern First-Principles View on Ligand Field Theory Through the Eyes of Correlated Multireference Wavefunctions. STRUCTURE AND BONDING 2011. [DOI: 10.1007/430_2011_57] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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34
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Camacho C, Witek HA, Cimiraglia R. The low-lying states of the scandium dimer. J Chem Phys 2010; 132:244306. [DOI: 10.1063/1.3442374] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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