1
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Kaiser S, Yue Z, Peng Y, Nguyen TD, Chen S, Teng D, Voth GA. Molecular Dynamics Simulation of Complex Reactivity with the Rapid Approach for Proton Transport and Other Reactions (RAPTOR) Software Package. J Phys Chem B 2024; 128:4959-4974. [PMID: 38742764 DOI: 10.1021/acs.jpcb.4c01987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Simulating chemically reactive phenomena such as proton transport on nanosecond to microsecond and beyond time scales is a challenging task. Ab initio methods are unable to currently access these time scales routinely, and traditional molecular dynamics methods feature fixed bonding arrangements that cannot account for changes in the system's bonding topology. The Multiscale Reactive Molecular Dynamics (MS-RMD) method, as implemented in the Rapid Approach for Proton Transport and Other Reactions (RAPTOR) software package for the LAMMPS molecular dynamics code, offers a method to routinely sample longer time scale reactive simulation data with statistical precision. RAPTOR may also be interfaced with enhanced sampling methods to drive simulations toward the analysis of reactive rare events, and a number of collective variables (CVs) have been developed to facilitate this. Key advances to this methodology, including GPU acceleration efforts and novel CVs to model water wire formation are reviewed, along with recent applications of the method which demonstrate its versatility and robustness.
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Affiliation(s)
- Scott Kaiser
- Department of Chemistry, Chicago Center for Theoretical Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
| | - Zhi Yue
- Department of Chemistry, Chicago Center for Theoretical Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
| | - Yuxing Peng
- NVIDIA Corporation, Santa Clara, California 95051, United States
| | - Trung Dac Nguyen
- Research Computing Center, The University of Chicago, Chicago, Illinois 60637, United States
| | - Sijia Chen
- Department of Chemistry, Chicago Center for Theoretical Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
| | - Da Teng
- Department of Chemistry, Chicago Center for Theoretical Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
| | - Gregory A Voth
- Department of Chemistry, Chicago Center for Theoretical Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
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2
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Kim B, Snyder R, Nagaraju M, Zhou Y, Ojeda-May P, Keeton S, Hege M, Shao Y, Pu J. Reaction Path-Force Matching in Collective Variables: Determining Ab Initio QM/MM Free Energy Profiles by Fitting Mean Force. J Chem Theory Comput 2021; 17:4961-4980. [PMID: 34283604 PMCID: PMC9064116 DOI: 10.1021/acs.jctc.1c00245] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
First-principles determination of free energy profiles for condensed-phase chemical reactions is hampered by the daunting costs associated with configurational sampling on ab initio quantum mechanical/molecular mechanical (AI/MM) potential energy surfaces. Here, we report a new method that enables efficient AI/MM free energy simulations through mean force fitting. In this method, a free energy path in collective variables (CVs) is first determined on an efficient reactive aiding potential. Based on the configurations sampled along the free energy path, correcting forces to reproduce the AI/MM forces on the CVs are determined through force matching. The AI/MM free energy profile is then predicted from simulations on the aiding potential in conjunction with the correcting forces. Such cycles of correction-prediction are repeated until convergence is established. As the instantaneous forces on the CVs sampled in equilibrium ensembles along the free energy path are fitted, this procedure faithfully restores the target free energy profile by reproducing the free energy mean forces. Due to its close connection with the reaction path-force matching (RP-FM) framework recently introduced by us, we designate the new method as RP-FM in collective variables (RP-FM-CV). We demonstrate the effectiveness of this method on a type-II solution-phase SN2 reaction, NH3 + CH3Cl (the Menshutkin reaction), simulated with an explicit water solvent. To obtain the AI/MM free energy profiles, we employed the semiempirical AM1/MM Hamiltonian as the base level for determining the string minimum free energy pathway, along which the free energy mean forces are fitted to various target AI/MM levels using the Hartree-Fock (HF) theory, density functional theory (DFT), and the second-order Møller-Plesset perturbation (MP2) theory as the AI method. The forces on the bond-breaking and bond-forming CVs at both the base and target levels are obtained by force transformation from Cartesian to redundant internal coordinates under the Wilson B-matrix formalism, where the linearized FM is facilitated by the use of spline functions. For the Menshutkin reaction tested, our FM treatment greatly reduces the deviations on the CV forces, originally in the range of 12-33 to ∼2 kcal/mol/Å. Comparisons with the experimental and benchmark AI/MM results, tests of the new method under a variety of simulation protocols, and analyses of the solute-solvent radial distribution functions suggest that RP-FM-CV can be used as an efficient, accurate, and robust method for simulating solution-phase chemical reactions.
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Affiliation(s)
- Bryant Kim
- Department of Chemistry and Chemical Biology, Indiana
University-Purdue University Indianapolis, 402 N. Blackford St., Indianapolis, IN
46202
| | - Ryan Snyder
- Department of Chemistry and Chemical Biology, Indiana
University-Purdue University Indianapolis, 402 N. Blackford St., Indianapolis, IN
46202
| | - Mulpuri Nagaraju
- Department of Chemistry and Chemical Biology, Indiana
University-Purdue University Indianapolis, 402 N. Blackford St., Indianapolis, IN
46202
| | - Yan Zhou
- Department of Chemistry and Chemical Biology, Indiana
University-Purdue University Indianapolis, 402 N. Blackford St., Indianapolis, IN
46202
| | - Pedro Ojeda-May
- Department of Chemistry and Chemical Biology, Indiana
University-Purdue University Indianapolis, 402 N. Blackford St., Indianapolis, IN
46202
| | - Seth Keeton
- Department of Chemistry and Chemical Biology, Indiana
University-Purdue University Indianapolis, 402 N. Blackford St., Indianapolis, IN
46202
| | - Mellisa Hege
- Department of Chemistry and Chemical Biology, Indiana
University-Purdue University Indianapolis, 402 N. Blackford St., Indianapolis, IN
46202
| | - Yihan Shao
- Department of Chemistry and Biochemistry, University of
Oklahoma, 101 Stephenson Pkwy, Norman, OK 73019
| | - Jingzhi Pu
- Department of Chemistry and Chemical Biology, Indiana
University-Purdue University Indianapolis, 402 N. Blackford St., Indianapolis, IN
46202
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3
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Sakti AW, Nishimura Y, Nakai H. Recent advances in quantum‐mechanical molecular dynamics simulations of proton transfer mechanism in various water‐based environments. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2020. [DOI: 10.1002/wcms.1419] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Aditya W. Sakti
- Element Strategy Initiative for Catalysts and Batteries (ESICB) Kyoto University Kyoto Japan
| | - Yoshifumi Nishimura
- Waseda Research Institute for Science and Engineering (WISE) Waseda University Tokyo Japan
| | - Hiromi Nakai
- Element Strategy Initiative for Catalysts and Batteries (ESICB) Kyoto University Kyoto Japan
- Waseda Research Institute for Science and Engineering (WISE) Waseda University Tokyo Japan
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering Waseda University Tokyo Japan
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4
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Li P, Jia X, Pan X, Shao Y, Mei Y. Accelerated Computation of Free Energy Profile at ab Initio Quantum Mechanical/Molecular Mechanics Accuracy via a Semi-Empirical Reference Potential. I. Weighted Thermodynamics Perturbation. J Chem Theory Comput 2018; 14:5583-5596. [DOI: 10.1021/acs.jctc.8b00571] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Pengfei Li
- State Key Laboratory of Precision Spectroscopy, School of Physics and Materials Science, East China Normal University, Shanghai 200062, China
| | - Xiangyu Jia
- State Key Laboratory of Precision Spectroscopy, School of Physics and Materials Science, East China Normal University, Shanghai 200062, China
| | - Xiaoliang Pan
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Yihan Shao
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Ye Mei
- State Key Laboratory of Precision Spectroscopy, School of Physics and Materials Science, East China Normal University, Shanghai 200062, China
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China
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5
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Chen C, Arntsen C, Voth GA. Development of reactive force fields using ab initio molecular dynamics simulation minimally biased to experimental data. J Chem Phys 2018; 147:161719. [PMID: 29096465 DOI: 10.1063/1.4985903] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Incorporation of quantum mechanical electronic structure data is necessary to properly capture the physics of many chemical processes. Proton hopping in water, which involves rearrangement of chemical and hydrogen bonds, is one such example of an inherently quantum mechanical process. Standard ab initio molecular dynamics (AIMD) methods, however, do not yet accurately predict the structure of water and are therefore less than optimal for developing force fields. We have instead utilized a recently developed method which minimally biases AIMD simulations to match limited experimental data to develop novel multiscale reactive molecular dynamics (MS-RMD) force fields by using relative entropy minimization. In this paper, we present two new MS-RMD models using such a parameterization: one which employs water with harmonic internal vibrations and another which uses anharmonic water. We show that the newly developed MS-RMD models very closely reproduce the solvation structure of the hydrated excess proton in the target AIMD data. We also find that the use of anharmonic water increases proton hopping, thereby increasing the proton diffusion constant.
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Affiliation(s)
- Chen Chen
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
| | - Christopher Arntsen
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
| | - Gregory A Voth
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
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6
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Izvekov S, Weingarten NS, Byrd EFC. Effect of a core-softened O–O interatomic interaction on the shock compression of fused silica. J Chem Phys 2018. [DOI: 10.1063/1.5017586] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Sergei Izvekov
- Weapons and Materials Research Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, Maryland 21005, USA
| | - N. Scott Weingarten
- Weapons and Materials Research Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, Maryland 21005, USA
| | - Edward F. C. Byrd
- Weapons and Materials Research Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, Maryland 21005, USA
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7
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Conformational landscapes of membrane proteins delineated by enhanced sampling molecular dynamics simulations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:909-926. [PMID: 29113819 DOI: 10.1016/j.bbamem.2017.10.033] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/24/2017] [Accepted: 10/28/2017] [Indexed: 11/22/2022]
Abstract
The expansion of computational power, better parameterization of force fields, and the development of novel algorithms to enhance the sampling of the free energy landscapes of proteins have allowed molecular dynamics (MD) simulations to become an indispensable tool to understand the function of biomolecules. The temporal and spatial resolution of MD simulations allows for the study of a vast number of processes of interest. Here, we review the computational efforts to uncover the conformational free energy landscapes of a subset of membrane proteins: ion channels, transporters and G-protein coupled receptors. We focus on the various enhanced sampling techniques used to study these questions, how the conclusions come together to build a coherent picture, and the relationship between simulation outcomes and experimental observables.
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8
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Arntsen C, Chen C, Voth GA. Reactive molecular dynamics models from ab initio molecular dynamics data using relative entropy minimization. Chem Phys Lett 2017; 683:573-578. [PMID: 28845049 PMCID: PMC5568817 DOI: 10.1016/j.cplett.2017.04.064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We present two new multiscale molecular dynamics (MS-RMD) models for the hydrated excess proton in water developed directly from ab initio molecular dynamics (AIMD) simulation data of the same system. The potential of mean force along the proton transfer reaction coordinate and radial distribution functions for the MS-RMD models are shown faithfully reproduce those of AIMD. The models are developed using an algorithm based on relative entropy minimization, thus demonstrating the ability of the method to rapidly generate accurate and highly efficient reactive MD force fields.
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Affiliation(s)
- Christopher Arntsen
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois, 60637 USA
| | - Chen Chen
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois, 60637 USA
- College of Chemistry and Molecular Sciences, Hubei Key Lab of Electrochemical Power Sources, Wuhan University, Wuhan, 430072 China
| | - Gregory A Voth
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois, 60637 USA
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9
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10
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Zhu G, Kang X, Zhou S, Tang X, Sha M, Cui Z, Xu X. Molecular insight into the microstructure and microscopic dynamics of pyridinium ionic liquids with different alkyl chains based on temperature response. RSC Adv 2017. [DOI: 10.1039/c6ra26866h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
High temperature is advantageous to the aggregation of the polar regions as well as the nonpolar regions of pyridinium ionic liquids.
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Affiliation(s)
- Guanglai Zhu
- Institute of Atomic and Molecular Physics
- Anhui Normal University
- Wuhu 241000
- China
| | - Xianqu Kang
- Institute of Atomic and Molecular Physics
- Anhui Normal University
- Wuhu 241000
- China
| | - Siwen Zhou
- Institute of Atomic and Molecular Physics
- Anhui Normal University
- Wuhu 241000
- China
| | - Xiaoshuan Tang
- Institute of Atomic and Molecular Physics
- Anhui Normal University
- Wuhu 241000
- China
| | - Maolin Sha
- Department of Chemistry and Chemical Engineering
- Hefei Normal University
- Hefei 230061
- China
| | - Zhifeng Cui
- Institute of Atomic and Molecular Physics
- Anhui Normal University
- Wuhu 241000
- China
| | - Xinsheng Xu
- Institute of Atomic and Molecular Physics
- Anhui Normal University
- Wuhu 241000
- China
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11
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Proton transfer pathways in an aspartate-water cluster sampled by a network of discrete states. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.07.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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12
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Zhou Y, Ojeda-May P, Nagaraju M, Pu J. Toward Determining ATPase Mechanism in ABC Transporters: Development of the Reaction Path-Force Matching QM/MM Method. Methods Enzymol 2016; 577:185-212. [PMID: 27498639 PMCID: PMC4985252 DOI: 10.1016/bs.mie.2016.05.054] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Adenosine triphosphate (ATP)-binding cassette (ABC) transporters are ubiquitous ATP-dependent membrane proteins involved in translocations of a wide variety of substrates across cellular membranes. To understand the chemomechanical coupling mechanism as well as functional asymmetry in these systems, a quantitative description of how ABC transporters hydrolyze ATP is needed. Complementary to experimental approaches, computer simulations based on combined quantum mechanical and molecular mechanical (QM/MM) potentials have provided new insights into the catalytic mechanism in ABC transporters. Quantitatively reliable determination of the free energy requirement for enzymatic ATP hydrolysis, however, requires substantial statistical sampling on QM/MM potential. A case study shows that brute force sampling of ab initio QM/MM (AI/MM) potential energy surfaces is computationally impractical for enzyme simulations of ABC transporters. On the other hand, existing semiempirical QM/MM (SE/MM) methods, although affordable for free energy sampling, are unreliable for studying ATP hydrolysis. To close this gap, a multiscale QM/MM approach named reaction path-force matching (RP-FM) has been developed. In RP-FM, specific reaction parameters for a selected SE method are optimized against AI reference data along reaction paths by employing the force matching technique. The feasibility of the method is demonstrated for a proton transfer reaction in the gas phase and in solution. The RP-FM method may offer a general tool for simulating complex enzyme systems such as ABC transporters.
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Affiliation(s)
- Y Zhou
- Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - P Ojeda-May
- Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - M Nagaraju
- Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - J Pu
- Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States.
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13
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Biswas R, Tse YLS, Tokmakoff A, Voth GA. Role of Presolvation and Anharmonicity in Aqueous Phase Hydrated Proton Solvation and Transport. J Phys Chem B 2015; 120:1793-804. [PMID: 26575795 DOI: 10.1021/acs.jpcb.5b09466] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Results from condensed phase ab initio molecular dynamics (AIMD) simulations suggest a proton transfer reaction is facilitated by "presolvation" in which the hydronium is transiently solvated by four water molecules, similar to the typical solvation structure of water, by accepting a weak hydrogen bond from the fourth water molecule. A new version 3.2 multistate empirical valence bond (MS-EVB 3.2) model for the hydrated excess proton incorporating this presolvation behavior is therefore developed. The classical MS-EVB simulations show similar structural properties as those of the previous model but with significantly improved diffusive behavior. The inclusion of nuclear quantum effects in the MS-EVB also provides an even better description of the proton diffusion rate. To quantify the influence of anharmonicity, a second model (aMS-EVB 3.2) is developed using the anharmonic aSPC/Fw water model, which provides similar structural properties but improved spectroscopic responses at high frequencies.
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Affiliation(s)
- Rajib Biswas
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago , Chicago, Illinois 60637, United States
| | - Ying-Lung Steve Tse
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago , Chicago, Illinois 60637, United States
| | - Andrei Tokmakoff
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago , Chicago, Illinois 60637, United States
| | - Gregory A Voth
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago , Chicago, Illinois 60637, United States
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14
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Mabuchi T, Fukushima A, Tokumasu T. A modified two-state empirical valence bond model for proton transport in aqueous solutions. J Chem Phys 2015; 143:014501. [DOI: 10.1063/1.4926394] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Takuya Mabuchi
- Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Akinori Fukushima
- Institute of Fluid Science, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Takashi Tokumasu
- Institute of Fluid Science, Tohoku University, Sendai, Miyagi 980-8577, Japan
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15
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Tse YLS, Knight C, Voth GA. An analysis of hydrated proton diffusion in ab initio molecular dynamics. J Chem Phys 2015; 142:014104. [DOI: 10.1063/1.4905077] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Ying-Lung Steve Tse
- Department of Chemistry, James Franck Institute, and Computation Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - Chris Knight
- Leadership Computing Facility, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Gregory A. Voth
- Department of Chemistry, James Franck Institute, and Computation Institute, University of Chicago, Chicago, Illinois 60637, USA
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16
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Do H, Troisi A. Developing accurate molecular mechanics force fields for conjugated molecular systems. Phys Chem Chem Phys 2015; 17:25123-32. [DOI: 10.1039/c5cp04328j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A rapid method to parameterize the intramolecular component of classical force fields is proposed and applied to a molecular semiconductor, oligomers of conjugated polymers and a biological chromophore.
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Affiliation(s)
- Hainam Do
- Department of Chemistry and Centre for Scientific Computing
- University of Warwick
- Coventry CV4 7AL
- UK
| | - Alessandro Troisi
- Department of Chemistry and Centre for Scientific Computing
- University of Warwick
- Coventry CV4 7AL
- UK
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17
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Cuny J, Hassanali AA. Ab Initio Molecular Dynamics Study of the Mechanism of Proton Recombination with a Weak Base. J Phys Chem B 2014; 118:13903-12. [DOI: 10.1021/jp507246e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Jérôme Cuny
- Laboratoire
de Chimie et Physique Quantiques (LCPQ), Université de Toulouse III [UPS] and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
- Department
of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich and Università della Svizzera Italiana, CH-6900 Lugano, Switzerland
| | - Ali A. Hassanali
- Condensed
Matter Physics Section, The Abdus Salaam International Center for Theoretical Physics, Strada Costiera 11, Trieste I-34151, Italy
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18
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Multiscale simulation reveals a multifaceted mechanism of proton permeation through the influenza A M2 proton channel. Proc Natl Acad Sci U S A 2014; 111:9396-401. [PMID: 24979779 DOI: 10.1073/pnas.1401997111] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The influenza A virus M2 channel (AM2) is crucial in the viral life cycle. Despite many previous experimental and computational studies, the mechanism of the activating process in which proton permeation acidifies the virion to release the viral RNA and core proteins is not well understood. Herein the AM2 proton permeation process has been systematically characterized using multiscale computer simulations, including quantum, classical, and reactive molecular dynamics methods. We report, to our knowledge, the first complete free-energy profiles for proton transport through the entire AM2 transmembrane domain at various pH values, including explicit treatment of excess proton charge delocalization and shuttling through the His37 tetrad. The free-energy profiles reveal that the excess proton must overcome a large free-energy barrier to diffuse to the His37 tetrad, where it is stabilized in a deep minimum reflecting the delocalization of the excess charge among the histidines and the cost of shuttling the proton past them. At lower pH values the His37 tetrad has a larger total charge that increases the channel width, hydration, and solvent dynamics, in agreement with recent 2D-IR spectroscopic studies. The proton transport barrier becomes smaller, despite the increased charge repulsion, due to backbone expansion and the more dynamic pore water molecules. The calculated conductances are in quantitative agreement with recent experimental measurements. In addition, the free-energy profiles and conductances for proton transport in several mutants provide insights for explaining our findings and those of previous experimental mutagenesis studies.
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19
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Zhou Y, Pu J. Reaction Path Force Matching: A New Strategy of Fitting Specific Reaction Parameters for Semiempirical Methods in Combined QM/MM Simulations. J Chem Theory Comput 2014; 10:3038-54. [PMID: 26588275 DOI: 10.1021/ct4009624] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a general strategy of reparametrizing semiempirical (SE) methods against ab initio (AI) methods for combined quantum mechanical and molecular mechanical (QM/MM) simulations of specific chemical reactions in condensed phases. The resulting approach, designated Reaction Path Force Matching (RP-FM), features cycles of sampling configurations along a reaction path on an efficient SE/MM potential energy surface (PES) and adjusting specific reaction parameters (SRPs) in the SE method such that the atomic forces computed at the target AI/MM level are reproduced. Iterative applications of the RP-FM cycle make possible achieving the accuracy of AI/MM simulations without explicitly sampling the computationally expensive AI/MM PES. The bypassed sampling, nevertheless, is implicitly accomplished through the aid of the efficient SE-SRP/MM PES, on which the target-level reaction path is expected to be obtained upon convergence. We demonstrate the effectiveness of the RP-FM procedure for a symmetric proton transfer reaction in the gas phase and in solution. The remarkable agreements between the RP-FM optimized SE-SRP methods and the target AI method on various properties, including energy profiles, potential of mean force free energy profiles, atomic forces, charge populations, and solvation effects, suggest that RP-FM can be used as an efficient and reliable strategy for simulating condensed-phase chemical reactions.
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Affiliation(s)
- Yan Zhou
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis , 402 N. Blackford St., LD326, Indianapolis, Indiana 46202, United States
| | - Jingzhi Pu
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis , 402 N. Blackford St., LD326, Indianapolis, Indiana 46202, United States
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20
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Nelson JG, Peng Y, Silverstein DW, Swanson JMJ. Multiscale Reactive Molecular Dynamics for Absolute p Ka Predictions and Amino Acid Deprotonation. J Chem Theory Comput 2014; 10:2729-2737. [PMID: 25061442 PMCID: PMC4095931 DOI: 10.1021/ct500250f] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Indexed: 01/16/2023]
Abstract
Accurately calculating a weak acid's pKa from simulations remains a challenging task. We report a multiscale theoretical approach to calculate the free energy profile for acid ionization, resulting in accurate absolute pKa values in addition to insights into the underlying mechanism. Importantly, our approach minimizes empiricism by mapping electronic structure data (QM/MM forces) into a reactive molecular dynamics model capable of extensive sampling. Consequently, the bulk property of interest (the absolute pKa) is the natural consequence of the model, not a parameter used to fit it. This approach is applied to create reactive models of aspartic and glutamic acids. We show that these models predict the correct pKa values and provide ample statistics to probe the molecular mechanism of dissociation. This analysis shows changes in the solvation structure and Zundel-dominated transitions between the protonated acid, contact ion pair, and bulk solvated excess proton.
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Affiliation(s)
- J Gard Nelson
- Department of Chemistry, Institute for Biophysical Dynamics, and Computation Institute, University of Chicago , 5735 S. Ellis Ave., Chicago, Illinois 60637, United States
| | - Yuxing Peng
- Department of Chemistry, Institute for Biophysical Dynamics, and Computation Institute, University of Chicago , 5735 S. Ellis Ave., Chicago, Illinois 60637, United States
| | - Daniel W Silverstein
- Department of Chemistry, Institute for Biophysical Dynamics, and Computation Institute, University of Chicago , 5735 S. Ellis Ave., Chicago, Illinois 60637, United States
| | - Jessica M J Swanson
- Department of Chemistry, Institute for Biophysical Dynamics, and Computation Institute, University of Chicago , 5735 S. Ellis Ave., Chicago, Illinois 60637, United States
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Hassanali AA, Cuny J, Verdolino V, Parrinello M. Aqueous solutions: state of the art in ab initio molecular dynamics. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2014; 372:20120482. [PMID: 24516179 DOI: 10.1098/rsta.2012.0482] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The simulation of liquids by ab initio molecular dynamics (AIMD) has been a subject of intense activity over the last two decades. The significant increase in computational resources as well as the development of new and efficient algorithms has elevated this method to the status of a standard quantum mechanical tool that is used by both experimentalists and theoreticians. As AIMD computes the electronic structure from first principles, it is free of ad hoc parametrizations and has thus been applied to a large variety of physical and chemical problems. In particular, AIMD has provided microscopic insight into the structural and dynamical properties of aqueous solutions which are often challenging to probe experimentally. In this review, after a brief theoretical description of the Born-Oppenheimer and Car-Parrinello molecular dynamics formalisms, we show how AIMD has enhanced our understanding of the properties of liquid water and its constituent ions: the proton and the hydroxide ion. Thereafter, a broad overview of the application of AIMD to other aqueous systems, such as solvated organic molecules and inorganic ions, is presented. We also briefly describe the latest theoretical developments made in AIMD, such as methods for enhanced sampling and the inclusion of nuclear quantum effects.
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Affiliation(s)
- Ali A Hassanali
- Department of Chemistry and Applied Biosciences, ETH Zurich and Università della Svizzera Italiana, , via G. Buffi 13, 6900 Lugano, Switzerland
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Hofer TS. Perspectives for hybrid ab initio/molecular mechanical simulations of solutions: from complex chemistry to proton-transfer reactions and interfaces. PURE APPL CHEM 2014. [DOI: 10.1515/pac-2014-5019] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
As a consequence of the ongoing development of enhanced computational resources, theoretical chemistry has become an increasingly valuable field for the investigation of a variety of chemical systems. Simulations employing a hybrid quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) technique have been shown to be a particularly promising approach, whenever ultrafast (i.e., picosecond) dynamical properties are to be studied, which are in many cases difficult to access via experimental techniques. Details of the quantum mechanical charge field (QMCF) ansatz, an advanced QM/MM protocol, are discussed and simulation results for various systems ranging from simple ionic hydrates to solvated organic molecules and coordination complexes in solution are presented. A particularly challenging application is the description of proton-transfer reactions in chemical simulations, which is a prerequisite to study acidified and basic systems. The methodical requirements for a combination of the QMCF methodology with a dissociative potential model for the description of the solvent are discussed. Furthermore, the possible extension of QM/MM approaches to solid/liquid interfaces is outlined.
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Doemer M, Maurer P, Campomanes P, Tavernelli I, Rothlisberger U. Generalized QM/MM Force Matching Approach Applied to the 11-cis Protonated Schiff Base Chromophore of Rhodopsin. J Chem Theory Comput 2013; 10:412-22. [PMID: 26579920 DOI: 10.1021/ct400697n] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We extended a previously developed force matching approach to systems with covalent QM/MM boundaries and describe its user-friendly implementation in the publicly available software package CPMD. We applied this approach to the challenging case of the retinal protonated Schiff base in dark state bovine rhodopsin. We were able to develop a highly accurate force field that is able to capture subtle structural changes within the chromophore that have a pronounced influence on the optical properties. The optical absorption spectrum calculated from configurations extracted from a MD trajectory using the new force field is in excellent agreement with QM/MM and experimental references.
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Affiliation(s)
- Manuel Doemer
- Laboratoire de Chimie et Biochimie Computationelle, Ecole Polytechnique Fédérale de Lausanne , Lausanne, CH-1025, Switzerland
| | - Patrick Maurer
- Laboratoire de Chimie et Biochimie Computationelle, Ecole Polytechnique Fédérale de Lausanne , Lausanne, CH-1025, Switzerland
| | - Pablo Campomanes
- Laboratoire de Chimie et Biochimie Computationelle, Ecole Polytechnique Fédérale de Lausanne , Lausanne, CH-1025, Switzerland
| | - Ivano Tavernelli
- Laboratoire de Chimie et Biochimie Computationelle, Ecole Polytechnique Fédérale de Lausanne , Lausanne, CH-1025, Switzerland
| | - Ursula Rothlisberger
- Laboratoire de Chimie et Biochimie Computationelle, Ecole Polytechnique Fédérale de Lausanne , Lausanne, CH-1025, Switzerland
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Abstract
The diffusion of protons through water is understood within the framework of the Grotthuss mechanism, which requires that they undergo structural diffusion in a stepwise manner throughout the water network. Despite long study, this picture oversimplifies and neglects the complexity of the supramolecular structure of water. We use first-principles simulations and demonstrate that the currently accepted picture of proton diffusion is in need of revision. We show that proton and hydroxide diffusion occurs through periods of intense activity involving concerted proton hopping followed by periods of rest. The picture that emerges is that proton transfer is a multiscale and multidynamical process involving a broader distribution of pathways and timescales than currently assumed. To rationalize these phenomena, we look at the 3D water network as a distribution of closed directed rings, which reveals the presence of medium-range directional correlations in the liquid. One of the natural consequences of this feature is that both the hydronium and hydroxide ion are decorated with proton wires. These wires serve as conduits for long proton jumps over several hydrogen bonds.
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Hofer TS. From macromolecules to electrons-grand challenges in theoretical and computational chemistry. Front Chem 2013; 1:6. [PMID: 24790935 PMCID: PMC3982537 DOI: 10.3389/fchem.2013.00006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 05/08/2013] [Indexed: 11/29/2022] Open
Affiliation(s)
- Thomas S. Hofer
- Theoretical Chemistry Division, Center for Chemistry and Biomedicine, Institute of General, Inorganic and Theoretical Chemistry, University of InnsbruckInnsbruck, Austria
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Abstract
Many processes important to chemistry, materials science, and biology cannot be described without considering electronic and nuclear-level dynamics and their coupling to slower, cooperative motions of the system. These inherently multiscale problems require computationally efficient and accurate methods to converge statistical properties. In this paper, a method is presented that uses data directly from condensed phase ab initio simulations to develop reactive molecular dynamics models that do not require predefined empirical functions. Instead, the interactions used in the reactive model are expressed as linear combinations of interpolating functions that are optimized by using a linear least-squares algorithm. One notable benefit of the procedure outlined here is the capability to minimize the number of parameters requiring nonlinear optimization. The method presented can be generally applied to multiscale problems and is demonstrated by generating reactive models for the hydrated excess proton and hydroxide ion based directly on condensed phase ab initio molecular dynamics simulations. The resulting models faithfully reproduce the water-ion structural properties and diffusion constants from the ab initio simulations. Additionally, the free energy profiles for proton transfer, which is sensitive to the structural diffusion of both ions in water, are reproduced. The high fidelity of these models to ab initio simulations will permit accurate modeling of general chemical reactions in condensed phase systems with computational efficiency orders of magnitudes greater than currently possible with ab initio simulation methods, thus facilitating a proper statistical sampling of the coupling to slow, large-scale motions of the system.
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Affiliation(s)
- Chris Knight
- Computing, Environment, and Life Sciences, Argonne National Laboratory, Argonne, Illinois 60439, USA
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Kumar R, Knight C, Voth GA. Exploring the behaviour of the hydrated excess proton at hydrophobic interfaces. Faraday Discuss 2013; 167:263-78. [DOI: 10.1039/c3fd00087g] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Jana A, Weyhermüller T, Mohanta S. Metal complex analogues of crown ethers as the preorganized motif to stabilize aquated proton in solid state. CrystEngComm 2013. [DOI: 10.1039/c3ce27075k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Wright LB, Rodger PM, Walsh TR. Aqueous citrate: a first-principles and force-field molecular dynamics study. RSC Adv 2013. [DOI: 10.1039/c3ra42437e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Yamashita T, Peng Y, Knight C, Voth GA. Computationally Efficient Multiconfigurational Reactive Molecular Dynamics. J Chem Theory Comput 2012; 8:4863-4875. [PMID: 25100924 DOI: 10.1021/ct3006437] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
It is a computationally demanding task to explicitly simulate the electronic degrees of freedom in a system to observe the chemical transformations of interest, while at the same time sampling the time and length scales required to converge statistical properties and thus reduce artifacts due to initial conditions, finite-size effects, and limited sampling. One solution that significantly reduces the computational expense consists of molecular models in which effective interactions between particles govern the dynamics of the system. If the interaction potentials in these models are developed to reproduce calculated properties from electronic structure calculations and/or ab initio molecular dynamics simulations, then one can calculate accurate properties at a fraction of the computational cost. Multiconfigurational algorithms model the system as a linear combination of several chemical bonding topologies to simulate chemical reactions, also sometimes referred to as "multistate". These algorithms typically utilize energy and force calculations already found in popular molecular dynamics software packages, thus facilitating their implementation without significant changes to the structure of the code. However, the evaluation of energies and forces for several bonding topologies per simulation step can lead to poor computational efficiency if redundancy is not efficiently removed, particularly with respect to the calculation of long-ranged Coulombic interactions. This paper presents accurate approximations (effective long-range interaction and resulting hybrid methods) and multiple-program parallelization strategies for the efficient calculation of electrostatic interactions in reactive molecular simulations.
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Affiliation(s)
- Takefumi Yamashita
- Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, the University of Tokyo, 4-6-1 Komaba, Tokyo, Japan
| | - Yuxing Peng
- Department of Chemistry, James Franck Institute, and Computation Institute, University of Chicago, Chicago, IL 6063
| | - Chris Knight
- Computing, Environment, and Life Sciences, Argonne National Laboratory, Argonne, IL 60439
| | - Gregory A Voth
- Department of Chemistry, James Franck Institute, and Computation Institute, University of Chicago, Chicago, IL 6063 ; Computing, Environment, and Life Sciences, Argonne National Laboratory, Argonne, IL 60439
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Knight C, Voth GA. Coarse-graining away electronic structure: a rigorous route to accurate condensed phase interaction potentials. Mol Phys 2012. [DOI: 10.1080/00268976.2012.668621] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Izvekov S, Rice BM. Mechanism of densification in silica glass under pressure as revealed by a bottom-up pairwise effective interaction model. J Chem Phys 2012; 136:134508. [DOI: 10.1063/1.3696865] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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Sala J, Guàrdia E, Martí J, Spångberg D, Masia M. Fitting properties from density functional theory based molecular dynamics simulations to parameterize a rigid water force field. J Chem Phys 2012; 136:054103. [DOI: 10.1063/1.3679402] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Abstract
Understanding the hydrated proton is a critically important problem that continues to engage the research efforts of chemists, physicists, and biologists because of its involvement in a wide array of phenomena. Only recently have several unique properties of the hydrated proton been unraveled through computer simulations. One such process is the detailed molecular mechanism by which protons hop between neighboring water molecules, thus giving rise to the anomalously high diffusion of protons relative to other simple cations. Termed Grotthuss shuttling, this process occurs over multiple time and length scales, presenting unique challenges for computer modeling and simulation. Because the hydrated proton is in reality a dynamical electronic charge defect that spans multiple water molecules, the simulation methodology must be able to dynamically readjust the chemical bonding topology. This reactive nature of the chemical process is automatically captured with ab initio molecular dynamics (AIMD) simulation methods, where the electronic degrees of freedom are treated explicitly. Unfortunately, these calculations can be prohibitively expensive for more complex proton solvation and transport phenomena in the condensed phase. These AIMD simulations remain extremely valuable, however, in validating empirical models, verifying results, and providing insight into molecular mechanisms. In this Account, we discuss recent progress in understanding the solvation and transport properties of the hydrated excess proton. The advances are based on results obtained from reactive molecular dynamics simulations using the multistate empirical valence bond (MS-EVB) methodology. This approach relies on a dynamic linear combination of chemical bond topologies to model charge delocalization and dynamic bonding environments. When parametrized via a variational force-matching algorithm from AIMD trajectories, the MS-EVB method can be viewed as a multiscale bridging of ab initio simulation results to a simpler and more efficient representation. The process allows sampling of longer time and length scales, which would normally be too computationally expensive with AIMD alone. With the MS-EVB methodology, the statistically important components of the excess proton solvation and hopping mechanisms in liquid water have been identified. The most likely solvation structure for the hydrated proton is a distorted Eigen-type complex (H(9)O(4)(+)). In this state, the excess proton charge defect rapidly resonates between three possible distorted Eigen-type structures until a successful proton hop occurs. This process, termed the "special-pair dance", serves as a kind of preparatory phase for the proton hopping while the neighboring water hydrogen-bonding network fluctuates and ultimately rearranges to facilitate a proton hop. The modifications of the solvation structure and transport properties of the excess proton in concentrated acid solutions were further investigated. The Eigen-type solvation structure also possesses both "hydrophilic" and "hydrophobic" sides, which accounts for the affinity of the hydrated proton for the air-water interface. This unusual "amphiphilic" character of the hydrated proton further leads to the metastable formation of contact ion pairs between two hydrated protons. It also engenders a surprisingly constant degree of solubility of hydrophobic species as a function of acid concentration, which contrasts with a markedly variable solubility as a function of salt (such as NaCl or KCl) concentration.
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Affiliation(s)
- Chris Knight
- Department of Chemistry, James Franck Institute, Institute for Biophysical Dynamics, and Computation Institute, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Gregory A. Voth
- Department of Chemistry, James Franck Institute, Institute for Biophysical Dynamics, and Computation Institute, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, United States
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