1
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Vuong VQ, Aradi B, Niklasson AMN, Cui Q, Irle S. Multipole Expansion of Atomic Electron Density Fluctuation Interactions in the Density-Functional Tight-Binding Method. J Chem Theory Comput 2023; 19:7592-7605. [PMID: 37890454 PMCID: PMC10821749 DOI: 10.1021/acs.jctc.3c00778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2023]
Abstract
The accuracy of the density-functional tight-binding (DFTB) method in describing noncovalent interactions is limited due to its reliance on monopole-based spherical charge densities. In this study, we present a multipole-extended second-order DFTB (mDFTB2) method that takes into account atomic dipole and quadrupole interactions. Furthermore, we combine the multipole expansion with the monopole-based third-order contribution, resulting in the mDFTB3 method. To assess the accuracy of mDFTB2 and mDFTB3, we evaluate their performance in describing noncovalent interactions, proton transfer barriers, and dipole moments. Our benchmark results show promising improvements even when using the existing electronic parameters optimized for the original DFTB3 model. Both mDFTB2 and mDFTB3 outperform their monopole-based counterparts, DFTB2 and DFTB3, in terms of accuracy. While mDFTB2 and mDFTB3 perform comparably for neutral and positively charged systems, mDFTB3 exhibits superior performance over mDFTB2 when dealing with negatively charged systems and proton transfers. Overall, the incorporation of the multipole expansion significantly enhances the accuracy of the DFTB method in describing noncovalent interactions and proton transfers.
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Affiliation(s)
- Van-Quan Vuong
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Bálint Aradi
- Bremen Center for Computational Materials Science, Universität Bremen, Bremen 28359, Germany
| | - Anders M N Niklasson
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Qiang Cui
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
- Department of Physics, Boston University, Boston, Massachusetts 02215, United States
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, United States
| | - Stephan Irle
- Computational Sciences & Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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2
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Uratani H, Yoshikawa T, Nakai H. Trajectory Surface Hopping Approach to Condensed-Phase Nonradiative Relaxation Dynamics Using Divide-and-Conquer Spin-Flip Time-Dependent Density-Functional Tight Binding. J Chem Theory Comput 2021; 17:1290-1300. [PMID: 33577323 DOI: 10.1021/acs.jctc.0c01155] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Nonradiative relaxation of excited molecules is central to many crucial issues in photochemistry. Condensed phases are typical contexts in which such problems are considered, and the nonradiative relaxation dynamics are expected to be significantly affected by interactions with the environment, for example, a solvent. We developed a nonadiabatic molecular dynamics simulation technique that can treat the nonradiative relaxation and explicitly include the environment in the calculations without a heavy computational burden. Specifically, we combined trajectory surface hopping with Tully's fewest-switches algorithm, a tight-binding approximated version of spin-flip time-dependent density-functional theory, and divide-and-conquer (DC) spatial fragmentation scheme. Numerical results showed that this method can treat systems with thousands of atoms within reasonable computational resources, and the error arising from DC fragmentation is negligibly small. Using this method, we obtained molecular insights into the solvent dependence of the photoexcited-state dynamics of trans-azobenzene, which demonstrate the importance of the environment for condensed-phase nonradiative relaxation.
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Affiliation(s)
- Hiroki Uratani
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Takeshi Yoshikawa
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan.,Waseda Research Institute for Science and Engineering (WISE), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Hiromi Nakai
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.,Waseda Research Institute for Science and Engineering (WISE), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.,Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Katsura, Kyoto 615-8245, Japan
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3
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Shi M, Jin X, Wan Z, He X. Automated fragmentation quantum mechanical calculation of 13C and 1H chemical shifts in molecular crystals. J Chem Phys 2021; 154:064502. [PMID: 33588539 DOI: 10.1063/5.0039115] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this work, the automated fragmentation quantum mechanics/molecular mechanics (AF-QM/MM) approach was applied to calculate the 13C and 1H nuclear magnetic resonance (NMR) chemical shifts in molecular crystals. Two benchmark sets of molecular crystals were selected to calculate the NMR chemical shifts. Systematic investigation was conducted to examine the convergence of AF-QM/MM calculations and the impact of various density functionals with different basis sets on the NMR chemical shift prediction. The result demonstrates that the calculated NMR chemical shifts are close to convergence when the distance threshold for the QM region is larger than 3.5 Å. For 13C chemical shift calculations, the mPW1PW91 functional is the best density functional among the functionals chosen in this study (namely, B3LYP, B3PW91, M06-2X, M06-L, mPW1PW91, OB98, and OPBE), while the OB98 functional is more suitable for the 1H NMR chemical shift prediction of molecular crystals. Moreover, with the B3LYP functional, at least a triple-ζ basis set should be utilized to accurately reproduce the experimental 13C and 1H chemical shifts. The employment of diffuse basis functions will further improve the accuracy for 13C chemical shift calculations, but not for the 1H chemical shift prediction. We further proposed a fragmentation scheme of dividing the central molecule into smaller fragments. By comparing with the results of the fragmentation scheme using the entire central molecule as the core region, the AF-QM/MM calculations with the fragmented central molecule can not only achieve accurate results but also reduce the computational cost. Therefore, the AF-QM/MM approach is capable of predicting the 13C and 1H NMR chemical shifts for molecular crystals accurately and effectively, and could be utilized for dealing with more complex periodic systems such as macromolecular polymers and biomacromolecules. The AF-QM/MM program for molecular crystals is available at https://github.com/shiman1995/NMR.
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Affiliation(s)
- Man Shi
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - Xinsheng Jin
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - Zheng Wan
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - Xiao He
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
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4
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Lee TS, Allen BK, Giese TJ, Guo Z, Li P, Lin C, McGee TD, Pearlman DA, Radak BK, Tao Y, Tsai HC, Xu H, Sherman W, York DM. Alchemical Binding Free Energy Calculations in AMBER20: Advances and Best Practices for Drug Discovery. J Chem Inf Model 2020; 60:5595-5623. [PMID: 32936637 PMCID: PMC7686026 DOI: 10.1021/acs.jcim.0c00613] [Citation(s) in RCA: 169] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Predicting protein-ligand binding affinities and the associated thermodynamics of biomolecular recognition is a primary objective of structure-based drug design. Alchemical free energy simulations offer a highly accurate and computationally efficient route to achieving this goal. While the AMBER molecular dynamics package has successfully been used for alchemical free energy simulations in academic research groups for decades, widespread impact in industrial drug discovery settings has been minimal because of the previous limitations within the AMBER alchemical code, coupled with challenges in system setup and postprocessing workflows. Through a close academia-industry collaboration we have addressed many of the previous limitations with an aim to improve accuracy, efficiency, and robustness of alchemical binding free energy simulations in industrial drug discovery applications. Here, we highlight some of the recent advances in AMBER20 with a focus on alchemical binding free energy (BFE) calculations, which are less computationally intensive than alternative binding free energy methods where full binding/unbinding paths are explored. In addition to scientific and technical advances in AMBER20, we also describe the essential practical aspects associated with running relative alchemical BFE calculations, along with recommendations for best practices, highlighting the importance not only of the alchemical simulation code but also the auxiliary functionalities and expertise required to obtain accurate and reliable results. This work is intended to provide a contemporary overview of the scientific, technical, and practical issues associated with running relative BFE simulations in AMBER20, with a focus on real-world drug discovery applications.
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Affiliation(s)
- Tai-Sung Lee
- Rutgers, the State University of New Jersey, Laboratory for Biomolecular Simulation Research, and Department of Chemistry and Chemical Biology, United States
| | - Bryce K. Allen
- Silicon Therapeutics, Boston, Massachusetts 02210, United States
| | - Timothy J. Giese
- Rutgers, the State University of New Jersey, Laboratory for Biomolecular Simulation Research, and Department of Chemistry and Chemical Biology, United States
| | - Zhenyu Guo
- Silicon Therapeutics, Boston, Massachusetts 02210, United States
| | - Pengfei Li
- Silicon Therapeutics, Boston, Massachusetts 02210, United States
| | - Charles Lin
- Silicon Therapeutics, Boston, Massachusetts 02210, United States
| | - T. Dwight McGee
- Silicon Therapeutics, Boston, Massachusetts 02210, United States
| | - David A. Pearlman
- QSimulate Incorporated, Cambridge, Massachusetts 02139, United States
| | - Brian K. Radak
- Silicon Therapeutics, Boston, Massachusetts 02210, United States
| | - Yujun Tao
- Rutgers, the State University of New Jersey, Laboratory for Biomolecular Simulation Research, and Department of Chemistry and Chemical Biology, United States
| | - Hsu-Chun Tsai
- Rutgers, the State University of New Jersey, Laboratory for Biomolecular Simulation Research, and Department of Chemistry and Chemical Biology, United States
| | - Huafeng Xu
- Silicon Therapeutics, Boston, Massachusetts 02210, United States
| | - Woody Sherman
- Silicon Therapeutics, Boston, Massachusetts 02210, United States
| | - Darrin M. York
- Rutgers, the State University of New Jersey, Laboratory for Biomolecular Simulation Research, and Department of Chemistry and Chemical Biology, United States
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5
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Uratani H, Nakai H. Non-adiabatic molecular dynamics with divide-and-conquer type large-scale excited-state calculations. J Chem Phys 2020; 152:224109. [DOI: 10.1063/5.0006831] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Hiroki Uratani
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Hiromi Nakai
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
- Waseda Research Institute for Science and Engineering (WISE), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
- Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Katsura, Kyoto 615-8245, Japan
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6
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Jones LO, Mosquera MA, Schatz GC, Ratner MA. Embedding Methods for Quantum Chemistry: Applications from Materials to Life Sciences. J Am Chem Soc 2020; 142:3281-3295. [PMID: 31986877 DOI: 10.1021/jacs.9b10780] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Quantum mechanical embedding methods hold the promise to transform not just the way calculations are performed, but to significantly reduce computational costs and improve scaling for macro-molecular systems containing hundreds if not thousands of atoms. The field of embedding has grown increasingly broad with many approaches of different intersecting flavors. In this perspective, we lay out the methods into two streams: QM:MM and QM:QM, showcasing the advantages and disadvantages of both. We provide a review of the literature, the underpinning theories including our contributions, and we highlight current applications with select examples spanning both materials and life sciences. We conclude with prospects and future outlook on embedding, and our view on the use of universal test case scenarios for cross-comparisons of the many available (and future) embedding theories.
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Affiliation(s)
- Leighton O Jones
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , United States
| | - Martín A Mosquera
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , United States
| | - George C Schatz
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , United States
| | - Mark A Ratner
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , United States
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7
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Giese TJ, York DM. Development of a Robust Indirect Approach for MM → QM Free Energy Calculations That Combines Force-Matched Reference Potential and Bennett's Acceptance Ratio Methods. J Chem Theory Comput 2019; 15:5543-5562. [PMID: 31507179 DOI: 10.1021/acs.jctc.9b00401] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We use the PBE0/6-31G* density functional method to perform ab initio quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) simulations under periodic boundary conditions with rigorous electrostatics using the ambient potential composite Ewald method in order to test the convergence of MM → QM/MM free energy corrections for the prediction of 17 small-molecule solvation free energies and eight ligand binding free energies to T4 lysozyme. The "indirect" thermodynamic cycle for calculating free energies is used to explore whether a series of reference potentials improve the statistical quality of the predictions. Specifically, we construct a series of reference potentials that optimize a molecular mechanical (MM) force field's parameters to reproduce the ab initio QM/MM forces from a QM/MM simulation. The optimizations form a systematic progression of successively expanded parameters that include bond, angle, dihedral, and charge parameters. For each reference potential, we calculate benchmark quality reference values for the MM → QM/MM correction by performing the mixed MM and QM/MM Hamiltonians at 11 intermediate states, each for 200 ps. We then compare forward and reverse application of Zwanzig's relation, thermodynamic integration (TI), and Bennett's acceptance ratio (BAR) methods as a function of reference potential, simulation time, and the number of simulated intermediate states. We find that Zwanzig's equation is inadequate unless a large number of intermediate states are explicitly simulated. The TI and BAR mean signed errors are very small even when only the end-state simulations are considered, and the standard deviations of the TI and BAR errors are decreased by choosing a reference potential that optimizes the bond and angle parameters. We find a robust approach for the data sets of fairly rigid molecules considered here is to use bond + angle reference potential together with the end-state-only BAR analysis. This requires QM/MM simulations to be performed in order to generate reference data to parametrize the bond + angle reference potential, and then this same simulation serves a dual purpose as the full QM/MM end state. The convergence of the results with respect to time suggests that computational resources may be used more efficiently by running multiple simulations for no more than 50 ps, rather than running one long simulation.
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Affiliation(s)
- Timothy J Giese
- Laboratory for Biomolecular Simulation Research, Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology , Rutgers University , Piscataway , New Jersey 08854-8087 , United States
| | - Darrin M York
- Laboratory for Biomolecular Simulation Research, Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology , Rutgers University , Piscataway , New Jersey 08854-8087 , United States
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8
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Staub R, Iannuzzi M, Khaliullin RZ, Steinmann SN. Energy Decomposition Analysis for Metal Surface-Adsorbate Interactions by Block Localized Wave Functions. J Chem Theory Comput 2018; 15:265-275. [PMID: 30462497 DOI: 10.1021/acs.jctc.8b00957] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The energy decomposition analysis based on block localized wave functions (BLW-EDA) allows one to gain physical insight into the nature of chemical bonding, decomposing the interaction energy in (1) a "frozen" term, accounting for the attraction due to electrostatic and dispersion interactions, modulated by Pauli repulsion, (2) the variationally assessed polarization energy, and (3) the charge transfer. This method has so far been applied to gas- and condensed-phase molecular systems. However, its standard version is not compatible with fractionally occupied orbitals (i.e., electronic smearing) and, as a consequence, cannot be applied to metallic surfaces. In this work, we propose a simple and practical extension of BLW-EDA to fractionally occupied orbitals, termed Ensemble BLW-EDA. As illustrative examples, we have applied the developed method to analyze the nature of the interaction of various adsorbates on Pt(111), ranging from physisorbed water to strongly chemisorbed ethylene. Our results show that polarization and charge transfer both contribute significantly at the adsorption minimum for all studied systems. The energy decomposition analysis provides details with respect to competing adsorption sites (e.g., CO on atop vs hollow sites) and elucidates the respective importance of polarization and charge transfer for the increased adsorption energy of H2S compared to H2O. Our development will enable a deeper understanding of the impact of charge transfer on catalytic processes in general.
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Affiliation(s)
- Ruben Staub
- Univ Lyon, Ecole Normale Supérieure de Lyon, CNRS Université Lyon 1 , Laboratoire de Chimie UMR 5182 , 46 allée d'Italie , Lyon , F-69364 , France
| | - Marcella Iannuzzi
- Institut für Chemie , University of Zurich , Winterthurerstrasse 190 , Zurich , CH-8057 , Switzerland
| | - Rustam Z Khaliullin
- Department of Chemistry , McGill University , 801 Sherbrooke Street West , Montreal , Québec H3A 0B8 , Canada
| | - Stephan N Steinmann
- Univ Lyon, Ecole Normale Supérieure de Lyon, CNRS Université Lyon 1 , Laboratoire de Chimie UMR 5182 , 46 allée d'Italie , Lyon , F-69364 , France
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9
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Kjellgren ER, Haugaard Olsen JM, Kongsted J. Importance of Accurate Structures for Quantum Chemistry Embedding Methods: Which Strategy Is Better? J Chem Theory Comput 2018; 14:4309-4319. [DOI: 10.1021/acs.jctc.8b00202] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Erik Rosendahl Kjellgren
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Jógvan Magnus Haugaard Olsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, UiT The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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10
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Christensen AS, Kromann JC, Jensen JH, Cui Q. Intermolecular interactions in the condensed phase: Evaluation of semi-empirical quantum mechanical methods. J Chem Phys 2018; 147:161704. [PMID: 29096452 DOI: 10.1063/1.4985605] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
To facilitate further development of approximate quantum mechanical methods for condensed phase applications, we present a new benchmark dataset of intermolecular interaction energies in the solution phase for a set of 15 dimers, each containing one charged monomer. The reference interaction energy in solution is computed via a thermodynamic cycle that integrates dimer binding energy in the gas phase at the coupled cluster level and solute-solvent interaction with density functional theory; the estimated uncertainty of such calculated interaction energy is ±1.5 kcal/mol. The dataset is used to benchmark the performance of a set of semi-empirical quantum mechanical (SQM) methods that include DFTB3-D3, DFTB3/CPE-D3, OM2-D3, PM6-D3, PM6-D3H+, and PM7 as well as the HF-3c method. We find that while all tested SQM methods tend to underestimate binding energies in the gas phase with a root-mean-squared error (RMSE) of 2-5 kcal/mol, they overestimate binding energies in the solution phase with an RMSE of 3-4 kcal/mol, with the exception of DFTB3/CPE-D3 and OM2-D3, for which the systematic deviation is less pronounced. In addition, we find that HF-3c systematically overestimates binding energies in both gas and solution phases. As most approximate QM methods are parametrized and evaluated using data measured or calculated in the gas phase, the dataset represents an important first step toward calibrating QM based methods for application in the condensed phase where polarization and exchange repulsion need to be treated in a balanced fashion.
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Affiliation(s)
- Anders S Christensen
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA
| | - Jimmy C Kromann
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Jan H Jensen
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Qiang Cui
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA
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11
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Grimme S, Bannwarth C, Caldeweyher E, Pisarek J, Hansen A. A general intermolecular force field based on tight-binding quantum chemical calculations. J Chem Phys 2017; 147:161708. [DOI: 10.1063/1.4991798] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie der Universität Bonn, Beringstr. 4, D-53115 Bonn,
Germany
| | - Christoph Bannwarth
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie der Universität Bonn, Beringstr. 4, D-53115 Bonn,
Germany
| | - Eike Caldeweyher
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie der Universität Bonn, Beringstr. 4, D-53115 Bonn,
Germany
| | - Jana Pisarek
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie der Universität Bonn, Beringstr. 4, D-53115 Bonn,
Germany
| | - Andreas Hansen
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie der Universität Bonn, Beringstr. 4, D-53115 Bonn,
Germany
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12
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Giese TJ, York DM. Quantum mechanical force fields for condensed phase molecular simulations. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:383002. [PMID: 28817382 PMCID: PMC5821073 DOI: 10.1088/1361-648x/aa7c5c] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Molecular simulations are powerful tools for providing atomic-level details into complex chemical and physical processes that occur in the condensed phase. For strongly interacting systems where quantum many-body effects are known to play an important role, density-functional methods are often used to provide the model with the potential energy used to drive dynamics. These methods, however, suffer from two major drawbacks. First, they are often too computationally intensive to practically apply to large systems over long time scales, limiting their scope of application. Second, there remain challenges for these models to obtain the necessary level of accuracy for weak non-bonded interactions to obtain quantitative accuracy for a wide range of condensed phase properties. Quantum mechanical force fields (QMFFs) provide a potential solution to both of these limitations. In this review, we address recent advances in the development of QMFFs for condensed phase simulations. In particular, we examine the development of QMFF models using both approximate and ab initio density-functional models, the treatment of short-ranged non-bonded and long-ranged electrostatic interactions, and stability issues in molecular dynamics calculations. Example calculations are provided for crystalline systems, liquid water, and ionic liquids. We conclude with a perspective for emerging challenges and future research directions.
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13
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Kuechler ER, Giese TJ, York DM. Charge-dependent many-body exchange and dispersion interactions in combined QM/MM simulations. J Chem Phys 2016; 143:234111. [PMID: 26696050 DOI: 10.1063/1.4937166] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Accurate modeling of the molecular environment is critical in condensed phase simulations of chemical reactions. Conventional quantum mechanical/molecular mechanical (QM/MM) simulations traditionally model non-electrostatic non-bonded interactions through an empirical Lennard-Jones (LJ) potential which, in violation of intuitive chemical principles, is bereft of any explicit coupling to an atom's local electronic structure. This oversight results in a model whereby short-ranged exchange-repulsion and long-ranged dispersion interactions are invariant to changes in the local atomic charge, leading to accuracy limitations for chemical reactions where significant atomic charge transfer can occur along the reaction coordinate. The present work presents a variational, charge-dependent exchange-repulsion and dispersion model, referred to as the charge-dependent exchange and dispersion (QXD) model, for hybrid QM/MM simulations. Analytic expressions for the energy and gradients are provided, as well as a description of the integration of the model into existing QM/MM frameworks, allowing QXD to replace traditional LJ interactions in simulations of reactive condensed phase systems. After initial validation against QM data, the method is demonstrated by capturing the solvation free energies of a series of small, chlorine-containing compounds that have varying charge on the chlorine atom. The model is further tested on the SN2 attack of a chloride anion on methylchloride. Results suggest that the QXD model, unlike the traditional LJ model, is able to simultaneously obtain accurate solvation free energies for a range of compounds while at the same time closely reproducing the experimental reaction free energy barrier. The QXD interaction model allows explicit coupling of atomic charge with many-body exchange and dispersion interactions that are related to atomic size and provides a more accurate and robust representation of non-electrostatic non-bonded QM/MM interactions.
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Affiliation(s)
- Erich R Kuechler
- BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087, USA
| | - Timothy J Giese
- BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087, USA
| | - Darrin M York
- BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087, USA
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14
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Giese TJ, Panteva MT, Chen H, York DM. Multipolar Ewald methods, 2: applications using a quantum mechanical force field. J Chem Theory Comput 2016; 11:451-61. [PMID: 25691830 PMCID: PMC4325604 DOI: 10.1021/ct500799g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Indexed: 01/08/2023]
Abstract
A fully quantum mechanical force field (QMFF) based on a modified “divide-and-conquer” (mDC) framework is applied to a series of molecular simulation applications, using a generalized Particle Mesh Ewald method extended to multipolar charge densities. Simulation results are presented for three example applications: liquid water, p-nitrophenylphosphate reactivity in solution, and crystalline N,N-dimethylglycine. Simulations of liquid water using a parametrized mDC model are compared to TIP3P and TIP4P/Ew water models and experiment. The mDC model is shown to be superior for cluster binding energies and generally comparable for bulk properties. Examination of the dissociative pathway for dephosphorylation of p-nitrophenylphosphate shows that the mDC method evaluated with the DFTB3/3OB and DFTB3/OPhyd semiempirical models bracket the experimental barrier, whereas DFTB2 and AM1/d-PhoT QM/MM simulations exhibit deficiencies in the barriers, the latter for which is related, in part, to the anomalous underestimation of the p-nitrophenylate leaving group pKa. Simulations of crystalline N,N-dimethylglycine are performed and the overall structure and atomic fluctuations are compared with the experiment and the general AMBER force field (GAFF). The QMFF, which was not parametrized for this application, was shown to be in better agreement with crystallographic data than GAFF. Our simulations highlight some of the application areas that may benefit from using new QMFFs, and they demonstrate progress toward the development of accurate QMFFs using the recently developed mDC framework.
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Affiliation(s)
- Timothy J Giese
- Center for Integrative Proteomics Research, BioMaPS Institute for Quantitative Biology and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087, United States
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15
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Giese TJ, York DM. Ambient-Potential Composite Ewald Method for ab Initio Quantum Mechanical/Molecular Mechanical Molecular Dynamics Simulation. J Chem Theory Comput 2016; 12:2611-32. [PMID: 27171914 DOI: 10.1021/acs.jctc.6b00198] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A new approach for performing Particle Mesh Ewald in ab initio quantum mechanical/molecular mechanical (QM/MM) simulations with extended atomic orbital basis sets is presented. The new approach, the Ambient-Potential Composite Ewald (CEw) method, does not perform the QM/MM interaction with Mulliken charges nor electrostatically fit charges. Instead the nuclei and electron density interact directly with the MM environment, but in a manner that avoids the use of dense Fourier transform grids. By performing the electrostatics with the underlying QM density, the CEw method avoids self-consistent field instabilities that have been encountered with simple charge mapping procedures. Potential of mean force (PMF) profiles of the p-nitrophenyl phosphate dissociation reaction in explicit solvent are computed from PBE0/6-31G* QM/MM molecular dynamics simulations with various electrostatic protocols. The CEw profiles are shown to be stable with respect to real-space Ewald cutoff, whereas the PMFs computed from truncated and switched electrostatics produce artifacts. PBE0/6-311G**, AM1/d-PhoT, and DFTB2 QM/MM simulations are performed to generate two-dimensional PMF profiles of the phosphoryl transesterification reactions with ethoxide and phenoxide leaving groups. The semiempirical models incorrectly produce a concerted ethoxide mechanism, whereas PBE0 correctly produces a stepwise mechanism. The ab initio reaction barriers agree more closely to experiment than the semiempirical models. The failure of Mulliken-charge QM/MM-Ewald is analyzed.
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Affiliation(s)
- Timothy J Giese
- Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology, Rutgers University , Piscataway, New Jersey 08854-8087, United States
| | - Darrin M York
- Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology, Rutgers University , Piscataway, New Jersey 08854-8087, United States
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16
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Christensen A, Kubař T, Cui Q, Elstner M. Semiempirical Quantum Mechanical Methods for Noncovalent Interactions for Chemical and Biochemical Applications. Chem Rev 2016; 116:5301-37. [PMID: 27074247 PMCID: PMC4867870 DOI: 10.1021/acs.chemrev.5b00584] [Citation(s) in RCA: 246] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Indexed: 12/28/2022]
Abstract
Semiempirical (SE) methods can be derived from either Hartree-Fock or density functional theory by applying systematic approximations, leading to efficient computational schemes that are several orders of magnitude faster than ab initio calculations. Such numerical efficiency, in combination with modern computational facilities and linear scaling algorithms, allows application of SE methods to very large molecular systems with extensive conformational sampling. To reliably model the structure, dynamics, and reactivity of biological and other soft matter systems, however, good accuracy for the description of noncovalent interactions is required. In this review, we analyze popular SE approaches in terms of their ability to model noncovalent interactions, especially in the context of describing biomolecules, water solution, and organic materials. We discuss the most significant errors and proposed correction schemes, and we review their performance using standard test sets of molecular systems for quantum chemical methods and several recent applications. The general goal is to highlight both the value and limitations of SE methods and stimulate further developments that allow them to effectively complement ab initio methods in the analysis of complex molecular systems.
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Affiliation(s)
- Anders
S. Christensen
- Department
of Chemistry and Theoretical Chemistry Institute, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Tomáš Kubař
- Institute of Physical
Chemistry & Center for Functional Nanostructures and Institute of Physical
Chemistry, Karlsruhe Institute of Technology, Kaiserstrasse 12, 76131 Karlsruhe, Germany
| | - Qiang Cui
- Department
of Chemistry and Theoretical Chemistry Institute, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Marcus Elstner
- Institute of Physical
Chemistry & Center for Functional Nanostructures and Institute of Physical
Chemistry, Karlsruhe Institute of Technology, Kaiserstrasse 12, 76131 Karlsruhe, Germany
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17
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Kuechler ER, Giese TJ, York DM. VR-SCOSMO: A smooth conductor-like screening model with charge-dependent radii for modeling chemical reactions. J Chem Phys 2016; 144:164115. [PMID: 27131539 PMCID: PMC4851621 DOI: 10.1063/1.4946779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/01/2016] [Indexed: 12/23/2022] Open
Abstract
To better represent the solvation effects observed along reaction pathways, and of ionic species in general, a charge-dependent variable-radii smooth conductor-like screening model (VR-SCOSMO) is developed. This model is implemented and parameterized with a third order density-functional tight binding quantum model, DFTB3/3OB-OPhyd, a quantum method which was developed for organic and biological compounds, utilizing a specific parameterization for phosphate hydrolysis reactions. Unlike most other applications with the DFTB3/3OB model, an auxiliary set of atomic multipoles is constructed from the underlying DFTB3 density matrix which is used to interact the solute with the solvent response surface. The resulting method is variational, produces smooth energies, and has analytic gradients. As a baseline, a conventional SCOSMO model with fixed radii is also parameterized. The SCOSMO and VR-SCOSMO models shown have comparable accuracy in reproducing neutral-molecule absolute solvation free energies; however, the VR-SCOSMO model is shown to reduce the mean unsigned errors (MUEs) of ionic compounds by half (about 2-3 kcal/mol). The VR-SCOSMO model presents similar accuracy as a charge-dependent Poisson-Boltzmann model introduced by Hou et al. [J. Chem. Theory Comput. 6, 2303 (2010)]. VR-SCOSMO is then used to examine the hydrolysis of trimethylphosphate and seven other phosphoryl transesterification reactions with different leaving groups. Two-dimensional energy landscapes are constructed for these reactions and calculated barriers are compared to those obtained from ab initio polarizable continuum calculations and experiment. Results of the VR-SCOSMO model are in good agreement in both cases, capturing the rate-limiting reaction barrier and the nature of the transition state.
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Affiliation(s)
- Erich R Kuechler
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087, USA
| | - Timothy J Giese
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087, USA
| | - Darrin M York
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087, USA
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18
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Huang M, Giese TJ, York DM. Nucleic acid reactivity: challenges for next-generation semiempirical quantum models. J Comput Chem 2015; 36:1370-89. [PMID: 25943338 PMCID: PMC4760688 DOI: 10.1002/jcc.23933] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 03/02/2015] [Accepted: 03/28/2015] [Indexed: 01/09/2023]
Abstract
Semiempirical quantum models are routinely used to study mechanisms of RNA catalysis and phosphoryl transfer reactions using combined quantum mechanical (QM)/molecular mechanical methods. Herein, we provide a broad assessment of the performance of existing semiempirical quantum models to describe nucleic acid structure and reactivity to quantify their limitations and guide the development of next-generation quantum models with improved accuracy. Neglect of diatomic differential overlap and self-consistent density-functional tight-binding semiempirical models are evaluated against high-level QM benchmark calculations for seven biologically important datasets. The datasets include: proton affinities, polarizabilities, nucleobase dimer interactions, dimethyl phosphate anion, nucleoside sugar and glycosidic torsion conformations, and RNA phosphoryl transfer model reactions. As an additional baseline, comparisons are made with several commonly used density-functional models, including M062X and B3LYP (in some cases with dispersion corrections). The results show that, among the semiempirical models examined, the AM1/d-PhoT model is the most robust at predicting proton affinities. AM1/d-PhoT and DFTB3-3ob/OPhyd reproduce the MP2 potential energy surfaces of 6 associative RNA phosphoryl transfer model reactions reasonably well. Further, a recently developed linear-scaling "modified divide-and-conquer" model exhibits the most accurate results for binding energies of both hydrogen bonded and stacked nucleobase dimers. The semiempirical models considered here are shown to underestimate the isotropic polarizabilities of neutral molecules by approximately 30%. The semiempirical models also fail to adequately describe torsion profiles for the dimethyl phosphate anion, the nucleoside sugar ring puckers, and the rotations about the nucleoside glycosidic bond. The modeling of pentavalent phosphorus, particularly with thio substitutions often used experimentally as mechanistic probes, was problematic for all of the models considered. Analysis of the strengths and weakness of the models suggests that the creation of robust next-generation models should emphasize the improvement of relative conformational energies and barriers, and nonbonded interactions.
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Affiliation(s)
- Ming Huang
- Scientific Computation, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN 55455–0431, USA
- Center for Integrative Proteomics Research, BioMaPS Institute for Quantitative Biology, and Department of Chemistry and Chemical Biology, Rutgers University, 174 Frelinghuysen Road, Piscataway, NJ 08854–8076, USA
| | - Timothy J. Giese
- Center for Integrative Proteomics Research, BioMaPS Institute for Quantitative Biology, and Department of Chemistry and Chemical Biology, Rutgers University, 174 Frelinghuysen Road, Piscataway, NJ 08854–8076, USA
| | - Darrin M. York
- Center for Integrative Proteomics Research, BioMaPS Institute for Quantitative Biology, and Department of Chemistry and Chemical Biology, Rutgers University, 174 Frelinghuysen Road, Piscataway, NJ 08854–8076, USA
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19
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Akimov AV, Prezhdo OV. Large-Scale Computations in Chemistry: A Bird’s Eye View of a Vibrant Field. Chem Rev 2015; 115:5797-890. [DOI: 10.1021/cr500524c] [Citation(s) in RCA: 159] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Alexey V. Akimov
- Department
of Chemistry, University of South California, Los Angeles, California 90089, United States
| | - Oleg V. Prezhdo
- Department
of Chemistry, University of South California, Los Angeles, California 90089, United States
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20
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Giese T, Panteva MT, Chen H, York DM. Multipolar Ewald methods, 1: theory, accuracy, and performance. J Chem Theory Comput 2015; 11:436-50. [PMID: 25691829 PMCID: PMC4325605 DOI: 10.1021/ct5007983] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Indexed: 11/29/2022]
Abstract
The Ewald, Particle Mesh Ewald (PME), and Fast Fourier–Poisson (FFP) methods are developed for systems composed of spherical multipole moment expansions. A unified set of equations is derived that takes advantage of a spherical tensor gradient operator formalism in both real space and reciprocal space to allow extension to arbitrary multipole order. The implementation of these methods into a novel linear-scaling modified “divide-and-conquer” (mDC) quantum mechanical force field is discussed. The evaluation times and relative force errors are compared between the three methods, as a function of multipole expansion order. Timings and errors are also compared within the context of the quantum mechanical force field, which encounters primary errors related to the quality of reproducing electrostatic forces for a given density matrix and secondary errors resulting from the propagation of the approximate electrostatics into the self-consistent field procedure, which yields a converged, variational, but nonetheless approximate density matrix. Condensed-phase simulations of an mDC water model are performed with the multipolar PME method and compared to an electrostatic cutoff method, which is shown to artificially increase the density of water and heat of vaporization relative to full electrostatic treatment.
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Affiliation(s)
- Timothy
J. Giese
- Center for Integrative Proteomics
Research, BioMaPS Institute for Quantitative Biology and Department
of Chemistry and Chemical Biology, Rutgers
University, Piscataway, New Jersey 08854-8087, United States
| | - Maria T. Panteva
- Center for Integrative Proteomics
Research, BioMaPS Institute for Quantitative Biology and Department
of Chemistry and Chemical Biology, Rutgers
University, Piscataway, New Jersey 08854-8087, United States
| | - Haoyuan Chen
- Center for Integrative Proteomics
Research, BioMaPS Institute for Quantitative Biology and Department
of Chemistry and Chemical Biology, Rutgers
University, Piscataway, New Jersey 08854-8087, United States
| | - Darrin M. York
- Center for Integrative Proteomics
Research, BioMaPS Institute for Quantitative Biology and Department
of Chemistry and Chemical Biology, Rutgers
University, Piscataway, New Jersey 08854-8087, United States
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21
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Panteva MT, Dissanayake T, Chen H, Radak BK, Kuechler ER, Giambaşu GM, Lee TS, York DM. Multiscale methods for computational RNA enzymology. Methods Enzymol 2015; 553:335-74. [PMID: 25726472 PMCID: PMC4739856 DOI: 10.1016/bs.mie.2014.10.064] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
RNA catalysis is of fundamental importance to biology and yet remains ill-understood due to its complex nature. The multidimensional "problem space" of RNA catalysis includes both local and global conformational rearrangements, changes in the ion atmosphere around nucleic acids and metal ion binding, dependence on potentially correlated protonation states of key residues, and bond breaking/forming in the chemical steps of the reaction. The goal of this chapter is to summarize and apply multiscale modeling methods in an effort to target the different parts of the RNA catalysis problem space while also addressing the limitations and pitfalls of these methods. Classical molecular dynamics simulations, reference interaction site model calculations, constant pH molecular dynamics (CpHMD) simulations, Hamiltonian replica exchange molecular dynamics, and quantum mechanical/molecular mechanical simulations will be discussed in the context of the study of RNA backbone cleavage transesterification. This reaction is catalyzed by both RNA and protein enzymes, and here we examine the different mechanistic strategies taken by the hepatitis delta virus ribozyme and RNase A.
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Affiliation(s)
- Maria T Panteva
- Center for Integrative Proteomics Research, BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Thakshila Dissanayake
- Center for Integrative Proteomics Research, BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Haoyuan Chen
- Center for Integrative Proteomics Research, BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Brian K Radak
- Center for Integrative Proteomics Research, BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Erich R Kuechler
- Center for Integrative Proteomics Research, BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - George M Giambaşu
- Center for Integrative Proteomics Research, BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Tai-Sung Lee
- Center for Integrative Proteomics Research, BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Darrin M York
- Center for Integrative Proteomics Research, BioMaPS Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA.
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22
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Goyal P, Qian HJ, Irle S, Lu X, Roston D, Mori T, Elstner M, Cui Q. Molecular simulation of water and hydration effects in different environments: challenges and developments for DFTB based models. J Phys Chem B 2014; 118:11007-27. [PMID: 25166899 PMCID: PMC4174991 DOI: 10.1021/jp503372v] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We discuss the description of water and hydration effects that employs an approximate density functional theory, DFTB3, in either a full QM or QM/MM framework. The goal is to explore, with the current formulation of DFTB3, the performance of this method for treating water in different chemical environments, the magnitude and nature of changes required to improve its performance, and factors that dictate its applicability to reactions in the condensed phase in a QM/MM framework. A relatively minor change (on the scale of kBT) in the O-H repulsive potential is observed to substantially improve the structural properties of bulk water under ambient conditions; modest improvements are also seen in dynamic properties of bulk water. This simple change also improves the description of protonated water clusters, a solvated proton, and to a more limited degree, a solvated hydroxide. By comparing results from DFTB3 models that differ in the description of water, we confirm that proton transfer energetics are adequately described by the standard DFTB3/3OB model for meaningful mechanistic analyses. For QM/MM applications, a robust parametrization of QM-MM interactions requires an explicit consideration of condensed phase properties, for which an efficient sampling technique was developed recently and is reviewed here. The discussions help make clear the value and limitations of DFTB3 based simulations, as well as the developments needed to further improve the accuracy and transferability of the methodology.
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Affiliation(s)
- Puja Goyal
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
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23
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Gao J, Truhlar DG, Wang Y, Mazack MJM, Löffler P, Provorse MR, Rehak P. Explicit polarization: a quantum mechanical framework for developing next generation force fields. Acc Chem Res 2014; 47:2837-45. [PMID: 25098651 PMCID: PMC4165456 DOI: 10.1021/ar5002186] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
![]()
Molecular mechanical force fields have been successfully used to
model condensed-phase and biological systems for a half century. By
means of careful parametrization, such classical force fields can
be used to provide useful interpretations of experimental findings
and predictions of certain properties. Yet, there is a need to further
improve computational accuracy for the quantitative prediction of
biomolecular interactions and to model properties that depend on the
wave functions and not just the energy terms. A new strategy called
explicit polarization (X-Pol) has been developed to construct the
potential energy surface and wave functions for macromolecular and
liquid-phase simulations on the basis of quantum mechanics rather
than only using quantum mechanical results to fit analytic force fields.
In this spirit, this approach is called a quantum mechanical force
field (QMFF). X-Pol is a general fragment method for electronic
structure calculations
based on the partition of a condensed-phase or macromolecular system
into subsystems (“fragments”) to achieve computational
efficiency. Here, intrafragment energy and the mutual electronic polarization
of interfragment interactions are treated explicitly using quantum
mechanics. X-Pol can be used as a general, multilevel electronic structure
model for macromolecular systems, and it can also serve as a new-generation
force field. As a quantum chemical model, a variational many-body
(VMB) expansion approach is used to systematically improve interfragment
interactions, including exchange repulsion, charge delocalization,
dispersion, and other correlation energies. As a quantum mechanical
force field, these energy terms are approximated by empirical functions
in the spirit of conventional molecular mechanics. This Account first
reviews the formulation of X-Pol, in the full variationally correct
version, in the faster embedded version, and with systematic many-body
improvements. We discuss illustrative examples involving water clusters
(which show the power of two-body corrections), ethylmethylimidazolium
acetate ionic liquids (which reveal that the amount of charge transfer
between anion and cation is much smaller than what has been assumed
in some classical simulations), and a solvated protein in aqueous
solution (which shows that the average charge distribution of carbonyl
groups along the polypeptide chain depends strongly on their position
in the sequence, whereas they are fixed in most classical force fields).
The development of QMFFs also offers an opportunity to extend the
accuracy of biochemical simulations to areas where classical force
fields are often insufficient, especially in the areas of spectroscopy,
reactivity, and enzyme catalysis.
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Affiliation(s)
- Jiali Gao
- Theoretical
Chemistry Institute, State Key Laboratory of Theoretical and Computational
Chemistry, Jilin University, Changchun, Jilin Province 130028, People’s Republic of China
- Department
of Chemistry and Supercomputing Institute University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Donald G. Truhlar
- Department
of Chemistry and Supercomputing Institute University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Yingjie Wang
- Department
of Chemistry and Supercomputing Institute University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Michael J. M. Mazack
- Department
of Chemistry and Supercomputing Institute University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Patrick Löffler
- Department
of Chemistry and Supercomputing Institute University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Makenzie R. Provorse
- Department
of Chemistry and Supercomputing Institute University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Pavel Rehak
- Department
of Chemistry and Supercomputing Institute University of Minnesota, Minneapolis, Minnesota 55455, United States
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24
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Giese TJ, Huang M, Chen H, York DM. Recent advances toward a general purpose linear-scaling quantum force field. Acc Chem Res 2014; 47:2812-20. [PMID: 24937206 PMCID: PMC4165466 DOI: 10.1021/ar500103g] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
![]()
There is need in the molecular simulation community to develop
new quantum mechanical (QM) methods that can be routinely applied
to the simulation of large molecular systems in complex, heterogeneous
condensed phase environments. Although conventional methods, such
as the hybrid quantum mechanical/molecular mechanical (QM/MM) method,
are adequate for many problems, there remain other applications that
demand a fully quantum mechanical approach. QM methods are generally
required in applications that involve changes in electronic structure,
such as when chemical bond formation or cleavage occurs, when molecules
respond to one another through polarization or charge transfer, or
when matter interacts with electromagnetic fields. A full QM treatment,
rather than QM/MM, is necessary when these features present themselves
over a wide spatial range that, in some cases, may span the entire
system. Specific examples include the study of catalytic events that
involve delocalized changes in chemical bonds, charge transfer, or
extensive polarization of the macromolecular environment; drug discovery
applications, where the wide range of nonstandard residues and protonation
states are challenging to model with purely empirical MM force fields;
and the interpretation of spectroscopic observables. Unfortunately,
the enormous computational cost of conventional QM methods limit their
practical application to small systems. Linear-scaling electronic
structure methods (LSQMs) make possible the calculation of large systems
but are still too computationally intensive to be applied with the
degree of configurational sampling often required to make meaningful
comparison with experiment. In this work, we present advances
in the development of a quantum
mechanical force field (QMFF) suitable for application to biological
macromolecules and condensed phase simulations. QMFFs leverage the
benefits provided by the LSQM and QM/MM approaches to produce a fully
QM method that is able to simultaneously achieve very high accuracy
and efficiency. The efficiency of the QMFF is made possible by partitioning
the system into fragments and self-consistently solving for the fragment-localized
molecular orbitals in the presence of the other fragment’s
electron densities. Unlike a LSQM, the QMFF introduces empirical parameters
that are tuned to obtain very accurate intermolecular forces. The
speed and accuracy of our QMFF is demonstrated through a series of
examples ranging from small molecule clusters to condensed phase simulation,
and applications to drug docking and protein–protein interactions.
In these examples, comparisons are made to conventional molecular
mechanical models, semiempirical methods, ab initio Hamiltonians, and a hybrid QM/MM method. The comparisons demonstrate
the superior accuracy of our QMFF relative to the other models; nonetheless,
we stress that the overarching role of QMFFs is not to supplant these
established computational methods for problems where their use is
appropriate. The role of QMFFs within the toolbox of multiscale modeling
methods is to extend the range of applications to include problems
that demand a fully quantum mechanical treatment of a large system
with extensive configurational sampling.
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Affiliation(s)
- Timothy J. Giese
- Center
for Integrative Proteomics Research, BioMaPS
Institute, and Department of Chemistry and
Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087 United States
| | - Ming Huang
- Center
for Integrative Proteomics Research, BioMaPS
Institute, and Department of Chemistry and
Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087 United States
- Scientific
Computation, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455−0431, United States
| | - Haoyuan Chen
- Center
for Integrative Proteomics Research, BioMaPS
Institute, and Department of Chemistry and
Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087 United States
| | - Darrin M. York
- Center
for Integrative Proteomics Research, BioMaPS
Institute, and Department of Chemistry and
Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8087 United States
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25
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Chaudret R, Gresh N, Narth C, Lagardère L, Darden TA, Cisneros GA, Piquemal JP. S/G-1: an ab initio force-field blending frozen Hermite Gaussian densities and distributed multipoles. Proof of concept and first applications to metal cations. J Phys Chem A 2014; 118:7598-612. [PMID: 24878003 DOI: 10.1021/jp5051657] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We demonstrate as a proof of principle the capabilities of a novel hybrid MM'/MM polarizable force field to integrate short-range quantum effects in molecular mechanics (MM) through the use of Gaussian electrostatics. This lead to a further gain in accuracy in the representation of the first coordination shell of metal ions. It uses advanced electrostatics and couples two point dipole polarizable force fields, namely, the Gaussian electrostatic model (GEM), a model based on density fitting, which uses fitted electronic densities to evaluate nonbonded interactions, and SIBFA (sum of interactions between fragments ab initio computed), which resorts to distributed multipoles. To understand the benefits of the use of Gaussian electrostatics, we evaluate first the accuracy of GEM, which is a pure density-based Gaussian electrostatics model on a test Ca(II)-H2O complex. GEM is shown to further improve the agreement of MM polarization with ab initio reference results. Indeed, GEM introduces nonclassical effects by modeling the short-range quantum behavior of electric fields and therefore enables a straightforward (and selective) inclusion of the sole overlap-dependent exchange-polarization repulsive contribution by means of a Gaussian damping function acting on the GEM fields. The S/G-1 scheme is then introduced. Upon limiting the use of Gaussian electrostatics to metal centers only, it is shown to be able to capture the dominant quantum effects at play on the metal coordination sphere. S/G-1 is able to accurately reproduce ab initio total interaction energies within closed-shell metal complexes regarding each individual contribution including the separate contributions of induction, polarization, and charge-transfer. Applications of the method are provided for various systems including the HIV-1 NCp7-Zn(II) metalloprotein. S/G-1 is then extended to heavy metal complexes. Tested on Hg(II) water complexes, S/G-1 is shown to accurately model polarization up to quadrupolar response level. This opens up the possibility of embodying explicit scalar relativistic effects in molecular mechanics thanks to the direct transferability of ab initio pseudopotentials. Therefore, incorporating GEM-like electron density for a metal cation enable the introduction of nonambiguous short-range quantum effects within any point-dipole based polarizable force field without the need of an extensive parametrization.
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Affiliation(s)
- Robin Chaudret
- Sorbonne Universités , UPMC, Univ Paris 06, UMR 7616, Laboratoire de Chimie Théorique, case courrier 137, 4 place Jussieu, F-75005 Paris, France
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26
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Zhou N, Lu Z, Wu Q, Zhang Y. Improved parameterization of interatomic potentials for rare gas dimers with density-based energy decomposition analysis. J Chem Phys 2014; 140:214117. [PMID: 24908000 PMCID: PMC4048451 DOI: 10.1063/1.4881255] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 05/21/2014] [Indexed: 11/14/2022] Open
Abstract
We examine interatomic interactions for rare gas dimers using the density-based energy decomposition analysis (DEDA) in conjunction with computational results from CCSD(T) at the complete basis set (CBS) limit. The unique DEDA capability of separating frozen density interactions from density relaxation contributions is employed to yield clean interaction components, and the results are found to be consistent with the typical physical picture that density relaxations play a very minimal role in rare gas interactions. Equipped with each interaction component as reference, we develop a new three-term molecular mechanical force field to describe rare gas dimers: a smeared charge multipole model for electrostatics with charge penetration effects, a B3LYP-D3 dispersion term for asymptotically correct long-range attractions that is screened at short-range, and a Born-Mayer exponential function for the repulsion. The resulted force field not only reproduces rare gas interaction energies calculated at the CCSD(T)/CBS level, but also yields each interaction component (electrostatic or van der Waals) which agrees very well with its corresponding reference value.
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Affiliation(s)
- Nengjie Zhou
- Department of Chemistry, New York University, New York, New York 10003, USA
| | - Zhenyu Lu
- Department of Chemistry, New York University, New York, New York 10003, USA
| | - Qin Wu
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Yingkai Zhang
- Department of Chemistry, New York University, New York, New York 10003, USA
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