1
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Antila HS, Dixit S, Kav B, Madsen JJ, Miettinen MS, Ollila OHS. Evaluating Polarizable Biomembrane Simulations against Experiments. J Chem Theory Comput 2024; 20:4325-4337. [PMID: 38718349 PMCID: PMC11137822 DOI: 10.1021/acs.jctc.3c01333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 04/10/2024] [Accepted: 04/10/2024] [Indexed: 05/29/2024]
Abstract
Owing to the increase of available computational capabilities and the potential for providing a more accurate description, polarizable molecular dynamics force fields are gaining popularity in modeling biomolecular systems. It is, however, crucial to evaluate how much precision is truly gained with increasing cost and complexity of the simulation. Here, we leverage the NMRlipids open collaboration and Databank to assess the performance of available polarizable lipid models─the CHARMM-Drude and the AMOEBA-based parameters─against high-fidelity experimental data and compare them to the top-performing nonpolarizable models. While some improvement in the description of ion binding to membranes is observed in the most recent CHARMM-Drude parameters, and the conformational dynamics of AMOEBA-based parameters are excellent, the best nonpolarizable models tend to outperform their polarizable counterparts for each property we explored. The identified shortcomings range from inaccuracies in describing the conformational space of lipids to excessively slow conformational dynamics. Our results provide valuable insights for the further refinement of polarizable lipid force fields and for selecting the best simulation parameters for specific applications.
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Affiliation(s)
- Hanne S. Antila
- Department
of Theory and Bio-Systems, Max Planck Institute
of Colloids and Interfaces, Potsdam 14476, Germany
- Department
of Biomedicine, University of Bergen, Bergen 5020, Norway
- Computational
Biology Unit, Department of Informatics, University of Bergen, Bergen 5008, Norway
| | - Sneha Dixit
- Department
of Theory and Bio-Systems, Max Planck Institute
of Colloids and Interfaces, Potsdam 14476, Germany
| | - Batuhan Kav
- Institute
of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jïulich 52428, Germany
| | - Jesper J. Madsen
- Department
of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612, United States
- Center
for Global Health and Infectious Diseases Research, Global and Planetary
Health, College of Public Health, University
of South Florida, Tampa, Florida 33612, United States of America
| | - Markus S. Miettinen
- Department
of Theory and Bio-Systems, Max Planck Institute
of Colloids and Interfaces, Potsdam 14476, Germany
- Computational
Biology Unit, Department of Informatics, University of Bergen, Bergen 5008, Norway
- Department
of Chemistry, University of Bergen, Bergen 5007, Norway
| | - O. H. Samuli Ollila
- VTT Technical
Research Centre of Finland, Espoo 02044, Finland
- Institute
of Biotechnology, University of Helsinki, Helsinki 00014, Finland
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2
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Mikkelsen JES, Jensen F. Ambiguities in Decomposing Molecular Polarizability into Atomic Charge Flow and Induced Dipole Contributions. J Phys Chem A 2024; 128:4168-4175. [PMID: 38743593 DOI: 10.1021/acs.jpca.4c01890] [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
The molecular dipole polarizability can be decomposed into components corresponding to the charge flow between atoms and changes in atomic dipole moments. Such decompositions are recognized to depend on how atoms are defined within a molecule, as, for example, by Hirshfeld, iterative Stockholder, or quantum topology partitioning of the electron density. For some of these, however, there are significant differences between the numerical results obtained by analytical response methods and finite field calculations. We show that this difference is due to analytical response methods accounting for (only) the change in electron density by a perturbation, while finite field methods may also include a component corresponding to a perturbation-dependent change in the definition of an atom within a molecule. For some atom-in-molecule definitions, such as the iterative Hirshfeld, iterative Stockholder, and quantum topology methods, the latter effect significantly increases the charge flow component. The decomposition of molecular polarizability into atomic charge flow and induced dipole components thus depends on whether the atom-in-molecule definition is taken to be perturbation-dependent.
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Affiliation(s)
- Jonas E S Mikkelsen
- Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus, Denmark
| | - Frank Jensen
- Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus, Denmark
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3
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Chung MKJ, Ponder JW. Beyond isotropic repulsion: Classical anisotropic repulsion by inclusion of p orbitals. J Chem Phys 2024; 160:174118. [PMID: 38748037 PMCID: PMC11078554 DOI: 10.1063/5.0203678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/15/2024] [Indexed: 05/19/2024] Open
Abstract
Accurate modeling of intermolecular repulsion is an integral component in force field development. Although repulsion can be explicitly calculated by applying the Pauli exclusion principle, this approach is computationally viable only for systems of limited sizes. Instead, it has previously been shown that repulsion can be reformulated in a "classical" picture: the Pauli exclusion principle prohibits electrons from occupying the same state, leading to a depletion of electronic charge between atoms, giving rise to an enhanced nuclear-nuclear electrostatic repulsion. This classical picture is called the isotropic S2/R approximation, where S is the overlap and R is the interatomic distance. This approximation accurately captures the repulsion of isotropic atoms such as noble gas dimers; however, a key deficiency is that it fails to capture the angular dependence of the repulsion of anisotropic molecules. To include directionality, the wave function must at least be a linear combination of s and p orbitals. We derive a new anisotropic S2/R repulsion model through the inclusion of the anisotropic p orbital term in the total wave function. Because repulsion is pairwise and decays rapidly, it can be truncated at a short range, making it amenable for efficient calculation of energy and forces in complex biomolecular systems. We present a parameterization of the S101 dimer database against the ab initio benchmark symmetry-adapted perturbation theory, which yields an rms error of only 0.9 kcal/mol. The importance of the anisotropic term is demonstrated through angular scans of water-water dimers and dimers involving halobenzene. Simulation of liquid water shows that the model can be computed efficiently for realistic system sizes.
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Affiliation(s)
| | - Jay W. Ponder
- Author to whom correspondence should be addressed: . Tel.: 314-935-4275
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4
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Nessler A, Okada O, Kinoshita Y, Nishimura K, Nagata H, Fukuzawa K, Yonemochi E, Schnieders MJ. Crystal Polymorph Search in the NPT Ensemble via a Deposition/Sublimation Alchemical Path. CRYSTAL GROWTH & DESIGN 2024; 24:3205-3217. [PMID: 38659664 PMCID: PMC11036363 DOI: 10.1021/acs.cgd.3c01358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 02/22/2024] [Accepted: 02/23/2024] [Indexed: 04/26/2024]
Abstract
The formulation of active pharmaceutical ingredients involves discovering stable crystal packing arrangements or polymorphs, each of which has distinct pharmaceutically relevant properties. Traditional experimental screening techniques utilizing various conditions are commonly supplemented with in silico crystal structure prediction (CSP) to inform the crystallization process and mitigate risk. Predictions are often based on advanced classical force fields or quantum mechanical calculations that model the crystal potential energy landscape but do not fully incorporate temperature, pressure, or solution conditions during the search procedure. This study proposes an innovative alchemical path that utilizes an advanced polarizable atomic multipole force field to predict crystal structures based on direct sampling of the NPT ensemble. The use of alchemical (i.e., nonphysical) intermediates, a novel Monte Carlo barostat, and an orthogonal space tempering bias combine to enhance the sampling efficiency of the deposition/sublimation phase transition. The proposed algorithm was applied to 2-((4-(2-(3,4-dichlorophenyl)ethyl)phenyl)amino)benzoic acid (Cambridge Crystallography Database Centre ID: XAFPAY) as a case study to showcase the algorithm. Each experimentally determined polymorph with one molecule in the asymmetric unit was successfully reproduced via approximately 1000 short 1 ns simulations per space group where each simulation was initiated from random rigid body coordinates and unit cell parameters. Utilizing two threads of a recent Intel CPU (a Xeon Gold 6330 CPU at 2.00 GHz), 1 ns of sampling using the polarizable AMOEBA force field can be acquired in 4 h (equating to more than 300 ns/day using all 112 threads/56 cores of a dual CPU node) within the Force Field X software (https://ffx.biochem.uiowa.edu). These results demonstrate a step forward in the rigorous use of the NPT ensemble during the CSP search process and open the door to future algorithms that incorporate solution conditions using continuum solvation methods.
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Affiliation(s)
- Aaron
J. Nessler
- Department
of Biomedical Engineering, University of
Iowa, 103 South Capitol
Street, 5601 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242, United States
| | - Okimasa Okada
- Sohyaku
Innovative Research Division, Mitsubishi
Tanabe Pharma Corporation, 1000 Kamoshida-cho, Aoba-ku, Yokohama, Kanagawa 227-0033, Japan
| | - Yuya Kinoshita
- Analytical
Development, Pharmaceutical Sciences, Takeda
Pharmaceutical Company Limited, 2-26-1, Muraoka-Higashi, Fujisawa 251-8555, Kanagawa, Japan
| | - Koki Nishimura
- Analytical
Development, Pharmaceutical Sciences, Takeda
Pharmaceutical Company Limited, 2-26-1, Muraoka-Higashi, Fujisawa 251-8555, Kanagawa, Japan
| | - Hiroomi Nagata
- CMC
Modality Technology Laboratories, Production Technology and Supply
Chain Management Division, Mitsubishi Tanabe
Pharma Corporation, Osaka 541-8505, Japan
| | - Kaori Fukuzawa
- Graduate
School of Pharmaceutical Sciences, Osaka
University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Etsuo Yonemochi
- Department
of Physical Chemistry, School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Michael J. Schnieders
- Department
of Biomedical Engineering, University of
Iowa, 103 South Capitol
Street, 5601 Seamans Center for the Engineering Arts and Sciences, Iowa City, Iowa 52242, United States
- Department
of Biochemistry, University of Iowa, 51 Newton Road, 4-403 Bowen Science
Building, Iowa City, Iowa 52242, United States
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5
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Kirsh JM, Weaver JB, Boxer SG, Kozuch J. Critical Evaluation of Polarizable and Nonpolarizable Force Fields for Proteins Using Experimentally Derived Nitrile Electric Fields. J Am Chem Soc 2024; 146:6983-6991. [PMID: 38415598 PMCID: PMC10941190 DOI: 10.1021/jacs.3c14775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
Molecular dynamics (MD) simulations are frequently carried out for proteins to investigate the role of electrostatics in their biological function. The choice of force field (FF) can significantly alter the MD results, as the simulated local electrostatic interactions lack benchmarking in the absence of appropriate experimental methods. We recently reported that the transition dipole moment (TDM) of the popular nitrile vibrational probe varies linearly with the environmental electric field, overcoming well-known hydrogen bonding (H-bonding) issues for the nitrile frequency and, thus, enabling the unambiguous measurement of electric fields in proteins (J. Am. Chem. Soc. 2022, 144 (17), 7562-7567). Herein, we utilize this new strategy to enable comparisons of experimental and simulated electric fields in protein environments. Specifically, previously determined TDM electric fields exerted onto nitrile-containing o-cyanophenylalanine residues in photoactive yellow protein are compared with MD electric fields from the fixed-charge AMBER FF and the polarizable AMOEBA FF. We observe that the electric field distributions for H-bonding nitriles are substantially affected by the choice of FF. As such, AMBER underestimates electric fields for nitriles experiencing moderate field strengths; in contrast, AMOEBA robustly recapitulates the TDM electric fields. The FF dependence of the electric fields can be partly explained by the presence of additional negative charge density along the nitrile bond axis in AMOEBA, which is due to the inclusion of higher-order multipole parameters; this, in turn, begets more head-on nitrile H-bonds. We conclude by discussing the implications of the FF dependence for the simulation of nitriles and proteins in general.
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Affiliation(s)
- Jacob M Kirsh
- Department of Chemistry, Stanford University, Stanford, California 94305-5012, United States
| | - Jared Bryce Weaver
- Department of Chemistry, Stanford University, Stanford, California 94305-5012, United States
| | - Steven G Boxer
- Department of Chemistry, Stanford University, Stanford, California 94305-5012, United States
| | - Jacek Kozuch
- Experimental Molecular Biophysics, Department of Physics, Freie Universität Berlin, 14195 Berlin, Germany
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6
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Valle JVL, Mendonça BHS, Barbosa MC, Chacham H, de Moraes EE. Accuracy of TIP4P/2005 and SPC/Fw Water Models. J Phys Chem B 2024; 128:1091-1097. [PMID: 38253517 DOI: 10.1021/acs.jpcb.3c07044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Water is used as the main solvent in model systems containing bioorganic molecules. Choosing the right water model is an important step in the study of the biophysical and biochemical processes that occur in cells. In the present work, we perform molecular dynamics simulations using two distinct force fields for water: the rigid model TIP4P/2005, where only intermolecular interactions are considered, and the flexible model SPC/Fw, where intramolecular interactions are also taken into account. The simulations aim to determine the effect of the inclusion of intramolecular interactions on the accuracy of calculated properties of bulk water (density and thermal expansion coefficient, self-diffusion coefficients, shear viscosity, radial distribution functions, and dielectric constant), as compared to experimental results, over a temperature range between 250 and 370 K. We find that the results of the rigid model present the smallest deviations relative to experiments for most of the calculated quantities, except for the shear viscosity of supercooled water and the water dielectric constant, where the flexible model presents better agreement with experiments.
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Affiliation(s)
- João V L Valle
- Instituto de Física, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador 40210-340, BA, Brazil
| | - Bruno H S Mendonça
- Departamento de Física, ICEX, Universidade Federal de Minas Gerais, CP 702, Belo Horizonte 30123-970, MG, Brazil
| | - Marcia C Barbosa
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, RS, Brazil
| | - Helio Chacham
- Departamento de Física, ICEX, Universidade Federal de Minas Gerais, CP 702, 30123-970 Belo Horizonte, MG, Brazil
| | - Elizane E de Moraes
- Instituto de Física, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador 40210-340, BA, Brazil
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7
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Thürlemann M, Riniker S. Hybrid classical/machine-learning force fields for the accurate description of molecular condensed-phase systems. Chem Sci 2023; 14:12661-12675. [PMID: 38020395 PMCID: PMC10646964 DOI: 10.1039/d3sc04317g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 10/24/2023] [Indexed: 12/01/2023] Open
Abstract
Electronic structure methods offer in principle accurate predictions of molecular properties, however, their applicability is limited by computational costs. Empirical methods are cheaper, but come with inherent approximations and are dependent on the quality and quantity of training data. The rise of machine learning (ML) force fields (FFs) exacerbates limitations related to training data even further, especially for condensed-phase systems for which the generation of large and high-quality training datasets is difficult. Here, we propose a hybrid ML/classical FF model that is parametrized exclusively on high-quality ab initio data of dimers and monomers in vacuum but is transferable to condensed-phase systems. The proposed hybrid model combines our previous ML-parametrized classical model with ML corrections for situations where classical approximations break down, thus combining the robustness and efficiency of classical FFs with the flexibility of ML. Extensive validation on benchmarking datasets and experimental condensed-phase data, including organic liquids and small-molecule crystal structures, showcases how the proposed approach may promote FF development and unlock the full potential of classical FFs.
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Affiliation(s)
- Moritz Thürlemann
- Department of Chemistry and Applied Biosciences, ETH Zürich Vladimir-Prelog-Weg 2 Zürich 8093 Switzerland
| | - Sereina Riniker
- Department of Chemistry and Applied Biosciences, ETH Zürich Vladimir-Prelog-Weg 2 Zürich 8093 Switzerland
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8
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Mendonça BHS, de Moraes EE, Kirch A, Batista RJC, de Oliveira AB, Barbosa MC, Chacham H. Flow through Deformed Carbon Nanotubes Predicted by Rigid and Flexible Water Models. J Phys Chem B 2023; 127:8634-8643. [PMID: 37754781 DOI: 10.1021/acs.jpcb.3c02889] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
Abstract
In this study, using nonequilibrium molecular dynamics simulation, the flow of water in deformed carbon nanotubes is studied for two water models TIP4P/2005 and simple point charge/FH (SPC/FH). The results demonstrated a nonuniform dependence of the flow on the tube deformation and the flexibility imposed on the water molecules, leading to an unexpected increase in the flow in some cases. The effects of the tube diameter and pressure gradient are investigated to explain the abnormal flow behavior with different degrees of structural deformation.
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Affiliation(s)
- Bruno H S Mendonça
- Departamento de Física, ICEX, Universidade Federal de Minas Gerais, CP 702, Belo Horizonte 30123-970, MG, Brazil
| | - Elizane E de Moraes
- Instituto de Física, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador 40210-340, BA, Brazil
| | - Alexsandro Kirch
- Instituto de Física, Universidade de São Paulo, CP 66318, São Paulo 05315-970, SP, Brazil
| | - Ronaldo J C Batista
- Departamento de Física, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto 35400-000, MG, Brazil
| | - Alan B de Oliveira
- Departamento de Física, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto 35400-000, MG, Brazil
| | - Marcia C Barbosa
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, RS, Brazil
| | - Hélio Chacham
- Departamento de Física, ICEX, Universidade Federal de Minas Gerais, CP 702, Belo Horizonte 30123-970, MG, Brazil
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9
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Herman KM, Stone AJ, Xantheas SS. Accurate Calculation of Many-Body Energies in Water Clusters Using a Classical Geometry-Dependent Induction Model. J Chem Theory Comput 2023; 19:6805-6815. [PMID: 37703063 DOI: 10.1021/acs.jctc.3c00575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
We incorporate geometry-dependent distributed multipole and polarizability surfaces into an induction model that is used to describe the 3- and 4-body terms of the interaction between water molecules. The moment expansion is carried out up to the hexadecapole with the multipoles distributed on the atom sites. Dipole-dipole, dipole-quadrupole, and quadrupole-quadrupole distributed polarizabilities are used to represent the response of the multipoles to an electric field. We compare the model against two large databases consisting of 43,844 3-body terms and 3,603 4-body terms obtained from high level ab initio calculations previously used to fit the MB-pol and q-AQUA classical interaction potentials for water. The classical induction model with no adjustable parameters reproduces the ab initio 3-/4-body terms contained in these two databases with a root-mean-square error (RMSE) of 0.104/0.058 and a mean-absolute error (MAE) of 0.054/0.026 kcal/mol, respectively. These results are on par with the ones obtained by fitting the same data using over 14,000 (for the 3-body) and 200 (for the 4-body) parameters via Permutationally Invariant Polynomials (PIPs). This demonstrates the accuracy of this physically motivated model in describing the 3- and 4-body terms in the interactions between water molecules with no adjustable parameters. The triple-dipole-dispersion energy, included in the calculation of the 3-body energy, was found to be small but not quite negligible. The model represents a practical, efficient, and transferable approach for obtaining accurate nonadditive interactions for multicomponent systems without the need to perform tens of thousands of high level electronic structure calculations and fitting them with PIPs.
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Affiliation(s)
- Kristina M Herman
- Department of Chemistry, University of Washington, Seattle, Washington 98185, United States
| | - Anthony J Stone
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K
| | - Sotiris S Xantheas
- Department of Chemistry, University of Washington, Seattle, Washington 98185, United States
- Advanced Computing Mathematics and Data Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MSIN J7-10, Richland, Washington 99352, United States
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10
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Wang X, Wang Y, Guo M, Wang X, Li Y, Zhang JZH. Assessment of an Electrostatic Energy-Based Charge Model for Modeling the Electrostatic Interactions in Water Solvent. J Chem Theory Comput 2023; 19:6294-6312. [PMID: 37656610 DOI: 10.1021/acs.jctc.3c00467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/03/2023]
Abstract
The protein force field based on the restrained electrostatic potential (RESP) charges has limitations in accurately describing hydrogen bonding interactions in proteins. To address this issue, we propose an alternative approach called the electrostatic energy-based charges (EEC) model, which shows improved performance in describing electrostatic interactions (EIs) of hydrogen bonds in proteins. In this study, we further investigate the performance of the EEC model in modeling EIs in water solvent. Our findings demonstrate that the fixed EEC model can effectively reproduce the quantum mechanics/molecular mechanics (QM/MM)-calculated EIs between a water molecule and various water solvent environments. However, to achieve the same level of computational accuracy, the electrostatic potential (ESP) charge model needs to fluctuate according to the electrostatic environment. Our analysis indicates that the requirement for charge adjustments depends on the specific mathematical and physical representation of EIs as a function of the environment for deriving charges. By comparing with widely used empirical water models calibrated to reproduce experimental properties, we confirm that the performance of the EEC model in reproducing QM/MM EIs is similar to that of general purpose TIP4P-like water models such as TIP4P-Ew and TIP4P/2005. When comparing the computed 10,000 distinct EI values within the range of -40 to 0 kcal/mol with the QM/MM results calculated at the MP2/aug-cc-pVQZ/TIP3P level, we noticed that the mean unsigned error (MUE) for the EEC model is merely 0.487 kcal/mol, which is remarkably similar to the MUE values of the TIP4P-Ew (0.63 kcal/mol) and TIP4P/2005 (0.579 kcal/mol) models. However, both the RESP method and the TIP3P model exhibit a tendency to overestimate the EIs, as evidenced by their higher MUE values of 1.761 and 1.293 kcal/mol, respectively. EEC-based molecular dynamics simulations have demonstrated that, when combined with appropriate van der Waals parameters, the EEC model can closely reproduce oxygen-oxygen radial distribution function and density of water, showing a remarkable similarity to the well-established TIP4P-like empirical water models. Our results demonstrate that the EEC model has the potential to build force fields with comparable accuracy to more sophisticated empirical TIP4P-like water models.
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Affiliation(s)
- Xianwei Wang
- College of Science, Zhejiang University of Technology, Hangzhou, Zhejiang 310023, China
| | - Yiying Wang
- College of Science, Zhejiang University of Technology, Hangzhou, Zhejiang 310023, China
| | - Man Guo
- College of Science, Zhejiang University of Technology, Hangzhou, Zhejiang 310023, China
| | - Xuechao Wang
- College of Science, Zhejiang University of Technology, Hangzhou, Zhejiang 310023, China
| | - Yang Li
- College of Information Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, China
| | - John Z H Zhang
- Shenzhen Institute of Synthetic Biology, Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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11
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Spronk SA, Glick ZL, Metcalf DP, Sherrill CD, Cheney DL. A quantum chemical interaction energy dataset for accurately modeling protein-ligand interactions. Sci Data 2023; 10:619. [PMID: 37699937 PMCID: PMC10497680 DOI: 10.1038/s41597-023-02443-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 08/03/2023] [Indexed: 09/14/2023] Open
Abstract
Fast and accurate calculation of intermolecular interaction energies is desirable for understanding many chemical and biological processes, including the binding of small molecules to proteins. The Splinter ["Symmetry-adapted perturbation theory (SAPT0) protein-ligand interaction"] dataset has been created to facilitate the development and improvement of methods for performing such calculations. Molecular fragments representing commonly found substructures in proteins and small-molecule ligands were paired into >9000 unique dimers, assembled into numerous configurations using an approach designed to adequately cover the breadth of the dimers' potential energy surfaces while enhancing sampling in favorable regions. ~1.5 million configurations of these dimers were randomly generated, and a structurally diverse subset of these were minimized to obtain an additional ~80 thousand local and global minima. For all >1.6 million configurations, SAPT0 calculations were performed with two basis sets to complete the dataset. It is expected that Splinter will be a useful benchmark dataset for training and testing various methods for the calculation of intermolecular interaction energies.
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Affiliation(s)
- Steven A Spronk
- Molecular Structure and Design, Bristol Myers Squibb Company, P. O. Box 5400, Princeton, NJ, 08543, USA.
| | - Zachary L Glick
- Center for Computational Molecular Science and Technology, School of Chemistry and Biochemistry, and School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
| | - Derek P Metcalf
- Center for Computational Molecular Science and Technology, School of Chemistry and Biochemistry, and School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
| | - C David Sherrill
- Center for Computational Molecular Science and Technology, School of Chemistry and Biochemistry, and School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA.
| | - Daniel L Cheney
- Molecular Structure and Design, Bristol Myers Squibb Company, P. O. Box 5400, Princeton, NJ, 08543, USA
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12
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Horton JT, Boothroyd S, Behara PK, Mobley DL, Cole DJ. A transferable double exponential potential for condensed phase simulations of small molecules. DIGITAL DISCOVERY 2023; 2:1178-1187. [PMID: 38013814 PMCID: PMC10408570 DOI: 10.1039/d3dd00070b] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 07/07/2023] [Indexed: 11/29/2023]
Abstract
The Lennard-Jones potential is the most widely-used function for the description of non-bonded interactions in transferable force fields for the condensed phase. This is not because it has an optimal functional form, but rather it is a legacy resulting from when computational expense was a major consideration and this potential was particularly convenient numerically. At present, it persists because the effort that would be required to re-write molecular modelling software and train new force fields has, until now, been prohibitive. Here, we present Smirnoff-plugins as a flexible framework to extend the Open Force Field software stack to allow custom force field functional forms. We deploy Smirnoff-plugins with the automated Open Force Field infrastructure to train a transferable, small molecule force field based on the recently-proposed double exponential functional form, on over 1000 experimental condensed phase properties. Extensive testing of the resulting force field shows improvements in transfer free energies, with acceptable conformational energetics, run times and convergence properties compared to state-of-the-art Lennard-Jones based force fields.
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Affiliation(s)
- Joshua T Horton
- School of Natural and Environmental Sciences, Newcastle University Newcastle upon Tyne NE1 7RU UK
| | | | - Pavan Kumar Behara
- Department of Pharmaceutical Sciences, University of California Irvine California 92697 USA
| | - David L Mobley
- Department of Pharmaceutical Sciences, University of California Irvine California 92697 USA
- Department of Chemistry, University of California Irvine California 92697 USA
| | - Daniel J Cole
- School of Natural and Environmental Sciences, Newcastle University Newcastle upon Tyne NE1 7RU UK
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13
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Wang W, Yan D, Cai Y, Xu D, Ma J, Wang Q. General Charge Transfer Dipole Model for AMOEBA-Like Force Fields. J Chem Theory Comput 2023; 19:2518-2534. [PMID: 37125725 DOI: 10.1021/acs.jctc.2c01084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The development of highly accurate force fields is always an importance aspect in molecular modeling. In this work, we introduce a general damping-based charge transfer dipole (D-CTD) model to describe the charge transfer energy and the corresponding charge flow for H, C, N, O, P, S, F, Cl, and Br elements in common bio-organic systems. Then, two effective schemes to evaluate the charge flow from the corresponding induced dipole moment between the interacting molecules were also proposed and discussed. The potential applicability of the D-CTD model in ion-containing systems was also demonstrated in a series of ion-water complexes including Li+, Na+, K+, Mg2+, Ca2+, Fe2+, Zn2+, Pt2+, F-, Cl-, Br-, and I- ions. In general, the D-CTD model demonstrated good accuracy and good transferability in both charge transfer energy and the corresponding charge flow for a wide range of model systems. By distinguishing the intermolecular charge redistribution (charge transfer) under the influence of an external electric field from the accompanying intramolecular charge redistribution (polarization), the D-CTD model is theoretically consistent with current induced dipole-based polarizable dipole models and hence can be easily implemented and parameterized. Along with our previous work in charge penetration-corrected electrostatics, a bottom-up approach constructed water model was also proposed and demonstrated. The structure-maker and structure-breaker roles of cations and anions were also correctly reproduced using Na+, K+, Cl-, and I- ions in the new water model, respectively. This work demonstrates a cost-effective approach to describe the charge transfer phenomena. The water and ion models also show the feasibility of a modulated development approach for future force fields.
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Affiliation(s)
- Wei Wang
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
| | - Dengjie Yan
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
| | - Yao Cai
- College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Dingguo Xu
- College of Chemistry, Sichuan University, Chengdu 610064, China
| | - Jianyi Ma
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
| | - Qiantao Wang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
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14
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Fossat MJ, Posey AE, Pappu RV. Uncovering the Contributions of Charge Regulation to the Stability of Single Alpha Helices. Chemphyschem 2023; 24:e202200746. [PMID: 36599672 PMCID: PMC10734359 DOI: 10.1002/cphc.202200746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 12/07/2022] [Indexed: 01/06/2023]
Abstract
The single alpha helix (SAH) is a recurring motif in biology. The consensus sequence has a di-block architecture that includes repeats of four consecutive glutamate residues followed by four consecutive lysine residues. Measurements show that the overall helicity of sequences with consensus E4 K4 repeats is insensitive to a wide range of pH values. Here, we use the recently introduced q-canonical ensemble, which allows us to decouple measurements of charge state and conformation, to explain the observed insensitivity of SAH helicity to pH. We couple the outputs from separate measurements of charge and conformation with atomistic simulations to derive residue-specific quantifications of preferences for being in an alpha helix and for the ionizable residues to be charged vs. uncharged. We find a clear preference for accommodating uncharged Glu residues within internal positions of SAH-forming sequences. The stabilities of alpha helical conformations increase with the number of E4 K4 repeats and so do the numbers of accessible charge states that are compatible with forming conformations of high helical content. There is conformational buffering whereby charge state heterogeneity buffers against large-scale conformational changes thus making the overall helicity insensitive to large changes in pH. Further, the results clearly argue against a single, rod-like alpha helical conformation being the only or even dominant conformation in the ensembles of so-called SAH sequences.
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Affiliation(s)
| | | | - Rohit V. Pappu
- Department of Biomedical Engineering and the Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130
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15
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Plé T, Mauger N, Adjoua O, Inizan TJ, Lagardère L, Huppert S, Piquemal JP. Routine Molecular Dynamics Simulations Including Nuclear Quantum Effects: From Force Fields to Machine Learning Potentials. J Chem Theory Comput 2023; 19:1432-1445. [PMID: 36856658 DOI: 10.1021/acs.jctc.2c01233] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
We report the implementation of a multi-CPU and multi-GPU massively parallel platform dedicated to the explicit inclusion of nuclear quantum effects (NQEs) in the Tinker-HP molecular dynamics (MD) package. The platform, denoted Quantum-HP, exploits two simulation strategies: the Ring-Polymer Molecular Dynamics (RPMD) that provides exact structural properties at the cost of a MD simulation in an extended space of multiple replicas and the adaptive Quantum Thermal Bath (adQTB) that imposes the quantum distribution of energy on a classical system via a generalized Langevin thermostat and provides computationally affordable and accurate (though approximate) NQEs. We discuss some implementation details, efficient numerical schemes, and parallelization strategies and quickly review the GPU acceleration of our code. Our implementation allows an efficient inclusion of NQEs in MD simulations for very large systems, as demonstrated by scaling tests on water boxes with more than 200,000 atoms (simulated using the AMOEBA polarizable force field). We test the compatibility of the approach with Tinker-HP's recently introduced Deep-HP machine learning potentials module by computing water properties using the DeePMD potential with adQTB thermostatting. Finally, we show that the platform is also compatible with the alchemical free energy estimation capabilities of Tinker-HP and fast enough to perform simulations. Therefore, we study how NQEs affect the hydration free energy of small molecules solvated with the recently developed Q-AMOEBA water force field. Overall, the Quantum-HP platform allows users to perform routine quantum MD simulations of large condensed-phase systems and will help to shed new light on the quantum nature of important interactions in biological matter.
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Affiliation(s)
- Thomas Plé
- Sorbonne Université, LCT, UMR 7616 CNRS, F-75005 Paris, France
| | - Nastasia Mauger
- Sorbonne Université, LCT, UMR 7616 CNRS, F-75005 Paris, France
| | - Olivier Adjoua
- Sorbonne Université, LCT, UMR 7616 CNRS, F-75005 Paris, France
| | | | - Louis Lagardère
- Sorbonne Université, LCT, UMR 7616 CNRS, F-75005 Paris, France
| | - Simon Huppert
- Institut des Nanosciences de Paris (INSP), CNRS UMR 7588, and Sorbonne Université, F-75005 Paris, France
| | - Jean-Philip Piquemal
- Sorbonne Université, LCT, UMR 7616 CNRS, F-75005 Paris, France.,Institut Universitaire de France, 75005 Paris, France.,Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
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16
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Herman KM, Xantheas SS. An extensive assessment of the performance of pairwise and many-body interaction potentials in reproducing ab initio benchmark binding energies for water clusters n = 2-25. Phys Chem Chem Phys 2023; 25:7120-7143. [PMID: 36853239 DOI: 10.1039/d2cp03241d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We assess the performance of 7 pairwise additive (TIP3P, TIP4P, TIP4P-ice, TIP5P, OPC, SPC, SPC/E) and 8 families of many-body potentials (q-AQUA, HIPPO, AMOEBA, EFP, TTM, WHBB, MB-pol, MB-UCB) in reproducing high-level ab initio benchmark values, CCSD(T) or MP2 at the complete basis set (CBS) limit for the binding energy and the many-body expansion (MBE) of water clusters n = 2-11, 16-17, 20, 25. By including a large range of cluster sizes having dissimilar hydrogen bonding networks, we obtain an understanding of how these potentials perform for different hydrogen bonding arrangements that are mostly outside of their parameterization range. While it is appropriate to compare the results of ab initio based many-body potentials directly to the electronic binding energies (De's), the pairwise additive ones are compared to the enthalpies at T = 298 K, ΔH(298 K), as the latter class of force fields are parametrized to reproduce enthalpies (implicitly accounting for zero-point energy corrections) rather than binding energies. We find that all pairwise additive potentials considered overestimate the reference ΔH values for the n = 2-25 clusters by >13%. For the water dimer (n = 2) in particular, the errors are in the range 83-119% for the pairwise additive potentials studied since these are based on an effective rather than the true 2-body interaction specifically designed as a means of partially accounting for the missing many-body terms. This stronger 2-body interaction is achieved by an enhanced monomer dipole moment that mimics its increase from the gas phase monomer to the condensed phase value. Indeed, for cluster sizes n ≥ 4 the percent deviations become slightly smaller (albeit all exceeding 13%). In contrast, we find that the many-body potentials perform more accurately in reproducing the electronic binding energies (De's) throughout the entire cluster range (n = 2-25), all reproducing the ab initio benchmark binding energies within ±7% of the respective CBS values. We further assess the ability of a subset of the many-body potentials (MB-UCB, q-AQUA, MB-pol, and TTM2.1-F) to also reproduce the magnitude of the ab initio many-body energy terms for water cluster sizes n = 7, 10, 16 and 17. The potentials show an overall good agreement with the available benchmark values. However, we identify characteristic differences upon comparing the many-body terms at both the ab initio-optimized geometries and the respective potential-optimized geometries to the reference ab initio values. Additionally, by applying this analysis to a wide range of cluster sizes, trends in the MBE of the potentials with increasing cluster size can be identified. Finally, in an attempt to draw a parallel between the pairwise additive and many-body potentials, we report the analysis of the individual molecular dipole moments for water clusters with 1 to ∼4 solvation shells with the TTM2.1-F potential. We find that the internally solvated water molecules have in general a larger molecular dipole moment ranging from 2.6-3.0 D. This justifies the use of an enhanced, with respect to the gas-phase value, molecular dipole moment for the pairwise additive potentials, which is intended to fold in the many body terms into an effective (enhanced) pairwise interaction through the choice of the charges. These results have important implications for the development of future generations of efficient, transferable, and highly accurate classical interaction potentials in both the pairwise additive and many-body categories.
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Affiliation(s)
- Kristina M Herman
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
| | - Sotiris S Xantheas
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA. .,Advanced Computing, Mathematics and Data Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MS K1-83, WA, 99352, USA.
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17
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Thürlemann M, Böselt L, Riniker S. Regularized by Physics: Graph Neural Network Parametrized Potentials for the Description of Intermolecular Interactions. J Chem Theory Comput 2023; 19:562-579. [PMID: 36633918 PMCID: PMC9878731 DOI: 10.1021/acs.jctc.2c00661] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Indexed: 01/13/2023]
Abstract
Simulations of molecular systems using electronic structure methods are still not feasible for many systems of biological importance. As a result, empirical methods such as force fields (FF) have become an established tool for the simulation of large and complex molecular systems. The parametrization of FF is, however, time-consuming and has traditionally been based on experimental data. Recent years have therefore seen increasing efforts to automatize FF parametrization or to replace FF with machine-learning (ML) based potentials. Here, we propose an alternative strategy to parametrize FF, which makes use of ML and gradient-descent based optimization while retaining a functional form founded in physics. Using a predefined functional form is shown to enable interpretability, robustness, and efficient simulations of large systems over long time scales. To demonstrate the strength of the proposed method, a fixed-charge and a polarizable model are trained on ab initio potential-energy surfaces. Given only information about the constituting elements, the molecular topology, and reference potential energies, the models successfully learn to assign atom types and corresponding FF parameters from scratch. The resulting models and parameters are validated on a wide range of experimentally and computationally derived properties of systems including dimers, pure liquids, and molecular crystals.
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Affiliation(s)
- Moritz Thürlemann
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Lennard Böselt
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Sereina Riniker
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
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18
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Witek J, Heindel JP, Guan X, Leven I, Hao H, Naullage P, LaCour A, Sami S, Menger MFSJ, Cofer-Shabica DV, Berquist E, Faraji S, Epifanovsky E, Head-Gordon T. M-Chem: a Modular Software Package for Molecular Simulation that Spans Scientific Domains. Mol Phys 2022; 121:e2129500. [PMID: 37470065 PMCID: PMC10353727 DOI: 10.1080/00268976.2022.2129500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 09/06/2022] [Indexed: 10/10/2022]
Abstract
We present a new software package called M-Chem that is designed from scratch in C++ and parallelized on shared-memory multi-core architectures to facilitate efficient molecular simulations. Currently, M-Chem is a fast molecular dynamics (MD) engine that supports the evaluation of energies and forces from two-body to many-body all-atom potentials, reactive force fields, coarse-grained models, combined quantum mechanics molecular mechanics (QM/MM) models, and external force drivers from machine learning, augmented by algorithms that are focused on gains in computational simulation times. M-Chem also includes a range of standard simulation capabilities including thermostats, barostats, multi-timestepping, and periodic cells, as well as newer methods such as fast extended Lagrangians and high quality electrostatic potential generation. At present M-Chem is a developer friendly environment in which we encourage new software contributors from diverse fields to build their algorithms, models, and methods in our modular framework. The long-term objective of M-Chem is to create an interdisciplinary platform for computational methods with applications ranging from biomolecular simulations, reactive chemistry, to materials research.
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Affiliation(s)
- Jagna Witek
- Kenneth S. Pitzer Theory Center and Department of Chemistry
| | - Joseph P Heindel
- Kenneth S. Pitzer Theory Center and Department of Chemistry
- Chemical Sciences Division, Lawrence Berkeley National Laboratory
| | - Xingyi Guan
- Kenneth S. Pitzer Theory Center and Department of Chemistry
- Chemical Sciences Division, Lawrence Berkeley National Laboratory
| | - Itai Leven
- Kenneth S. Pitzer Theory Center and Department of Chemistry
| | - Hongxia Hao
- Kenneth S. Pitzer Theory Center and Department of Chemistry
| | | | - Allen LaCour
- Kenneth S. Pitzer Theory Center and Department of Chemistry
- Chemical Sciences Division, Lawrence Berkeley National Laboratory
| | - Selim Sami
- Kenneth S. Pitzer Theory Center and Department of Chemistry
| | - M F S J Menger
- Stratingh Institute for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
| | - D Vale Cofer-Shabica
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19128 USA
| | - Eric Berquist
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, USA
| | - Shirin Faraji
- Stratingh Institute for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Evgeny Epifanovsky
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, USA
| | - Teresa Head-Gordon
- Kenneth S. Pitzer Theory Center and Department of Chemistry
- Chemical Sciences Division, Lawrence Berkeley National Laboratory
- Department of Bioengineering and Chemical and Biomolecular Engineering University of California, Berkeley, CA, USA
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19
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Chung MKJ, Wang Z, Rackers JA, Ponder JW. Classical Exchange Polarization: An Anisotropic Variable Polarizability Model. J Phys Chem B 2022; 126:7579-7594. [PMID: 36166814 PMCID: PMC10868659 DOI: 10.1021/acs.jpcb.2c04237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polarizability, or the tendency of the electron distribution to distort under an electric field, often depends on the local chemical environment. For example, the polarizability of a chloride ion is larger in gas phase compared to a chloride ion solvated in water. This effect is due to the restriction the Pauli exclusion principle places on the allowed electron states. Because no two electrons can occupy the same state, when a highly polarizable atom comes in close contact with other atoms or molecules, the space of allowed states can dramatically decrease. This constraint suggests that an accurate molecular mechanics polarizability model should depend on the radial distance between neighboring atoms. This paper introduces a variable polarizability model within the framework of the HIPPO (Hydrogen-like Intermolecular Polarizable Potential) force field, by damping the polarizability as a function of the orbital overlap of two atoms. This effectively captures the quantum mechanical exchange polarization effects, without explicit utilization of antisymmetrized wave functions. We show that the variable polarizability model remarkably improves the two-body polarization energies and three-body energies of ion-ion and ion-water systems. Under this model, no manual tuning of atomic polarizabilities for monatomic ions is required; the gas-phase polarizability can be used because an appropriate damping function is able to correct the polarizability at short range.
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Affiliation(s)
- Moses K. J. Chung
- Medical Scientist Training Program, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Department of Physics, Washington University in St. Louis, Saint Louis, MO 63130, USA
| | - Zhi Wang
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO 63130, USA
| | - Joshua A. Rackers
- Center for Computing Research, Sandia National Laboratories, Albuquerque, NM 87185, USA
| | - Jay W. Ponder
- Department of Chemistry, Washington University in St. Louis, Saint Louis, MO 63130, USA
- Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO 63110, USA
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20
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Symons BCB, Popelier PLA. Application of Quantum Chemical Topology Force Field FFLUX to Condensed Matter Simulations: Liquid Water. J Chem Theory Comput 2022; 18:5577-5588. [PMID: 35939826 PMCID: PMC9476653 DOI: 10.1021/acs.jctc.2c00311] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
We present here the first application of the quantum
chemical topology
force field FFLUX to condensed matter simulations. FFLUX offers many-body
potential energy surfaces learnt exclusively from ab initio data using Gaussian process regression. FFLUX also includes high-rank,
polarizable multipole moments (up to quadrupole moments in this work)
that are learnt from the same ab initio calculations
as the potential energy surfaces. Many-body effects (where a body
is an atom) and polarization are captured by the machine learning
models. The choice to use machine learning in this way allows the
force field’s representation of reality to be improved (e.g., by including higher order many-body effects) with
little detriment to the computational scaling of the code. In this
manner, FFLUX is inherently future-proof. The “plug and play”
nature of the machine learning models also ensures that FFLUX can
be applied to any system of interest, not just liquid water. In this
work we study liquid water across a range of temperatures and compare
the predicted bulk properties to experiment as well as other state-of-the-art
force fields AMOEBA(+CF), HIPPO, MB-Pol and SIBFA21. We find that
FFLUX finds a place amongst these.
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Affiliation(s)
- Benjamin C B Symons
- Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, Great Britain
| | - Paul L A Popelier
- Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, Great Britain
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21
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Symons BCB, Popelier PLA. Flexible multipole moments in smooth particle mesh Ewald. J Chem Phys 2022; 156:244107. [DOI: 10.1063/5.0095581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The smooth particle mesh Ewald sum is extended with additional force terms that arise from the so-called flexible multipole moments. These are multipole moments (of any rank) that depend explicitly on atomic positions in some local environment that can be made arbitrarily large. By introducing explicit dependence on atomic positions, flexible multipole moments are polarized by their local environment, allowing both intramolecular and intermolecular polarizations to be captured. Multipolar torques are discussed in detail, and it is shown that they arise naturally in the presented framework. Furthermore, we give details of how we validated our implementation of the flexible smooth particle mesh Ewald sum by considering two mathematical limits of the smooth particle mesh Ewald summation.
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Affiliation(s)
- Benjamin C. B. Symons
- Department of Chemistry, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Paul L. A. Popelier
- Department of Chemistry, The University of Manchester, Manchester M13 9PL, United Kingdom
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22
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Naseem-Khan S, Lagardère L, Narth C, Cisneros GA, Ren P, Gresh N, Piquemal JP. Development of the Quantum-Inspired SIBFA Many-Body Polarizable Force Field: Enabling Condensed-Phase Molecular Dynamics Simulations. J Chem Theory Comput 2022; 18:3607-3621. [PMID: 35575306 PMCID: PMC10851344 DOI: 10.1021/acs.jctc.2c00029] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We present the extension of the Sum of Interactions Between Fragments Ab initio Computed (SIBFA) many-body polarizable force field to condensed-phase molecular dynamics (MD) simulations. The quantum-inspired SIBFA procedure is grounded on simplified integrals obtained from localized molecular orbital theory and achieves full separability of its intermolecular potential. It embodies long-range multipolar electrostatics (up to quadrupole) coupled to a short-range penetration correction (up to charge-quadrupole), exchange repulsion, many-body polarization, many-body charge transfer/delocalization, exchange dispersion, and dispersion (up to C10). This enables the reproduction of all energy contributions of ab initio symmetry-adapted perturbation theory (SAPT(DFT)) gas-phase reference computations. The SIBFA approach has been integrated within the Tinker-HP massively parallel MD package. To do so, all SIBFA energy gradients have been derived and the approach has been extended to enable periodic boundary conditions simulations using smooth particle mesh Ewald. This novel implementation also notably includes a computationally tractable simplification of the many-body charge transfer/delocalization contribution. As a proof of concept, we perform a first computational experiment defining a water model fitted on a limited set of SAPT(DFT) data. SIBFA is shown to enable a satisfactory reproduction of both gas-phase energetic contributions and condensed-phase properties highlighting the importance of its physically motivated functional form.
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Affiliation(s)
- Sehr Naseem-Khan
- LCT, UMR 7616 CNRS, Sorbonne Université, 75005 Paris, France
- Department of Chemistry, University of North Texas, Denton, Texas 76201, United States
| | - Louis Lagardère
- LCT, UMR 7616 CNRS, Sorbonne Université, 75005 Paris, France
- IP2CT, FR 2622, CNRS, Sorbonne Université, 75005 Paris, France
| | | | - G Andrés Cisneros
- Department of Chemistry, University of North Texas, Denton, Texas 76201, United States
| | - Pengyu Ren
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Nohad Gresh
- LCT, UMR 7616 CNRS, Sorbonne Université, 75005 Paris, France
| | - Jean-Philip Piquemal
- LCT, UMR 7616 CNRS, Sorbonne Université, 75005 Paris, France
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Institut Universitaire de France, 75005 Paris, France
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23
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Abstract
We review different models for introducing electric polarization in force fields, with special focus on methods where polarization is modelled at the atomic charge level. While electric polarization has been included in several force fields, the common approach has been to focus on atomic dipole polarizability. Several approaches allow modelling electric polarization by using charge-flow between charge sites instead, but this has been less exploited, despite that atomic charges and charge-flow is expected to be more important than atomic dipoles and dipole polarizability. A number of challenges are required to be solved for charge-flow models to be incorporated into polarizable force fields, for example how to parameterize the models and how to make them computational efficient.
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Affiliation(s)
- Frank Jensen
- Department of Chemistry, Aarhus University, Denmark.
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24
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Naseem-Khan S, Piquemal JP, Cisneros GA. Improvement of the Gaussian Electrostatic Model by separate fitting of Coulomb and exchange-repulsion densities and implementation of a new dispersion term. J Chem Phys 2021; 155:194103. [PMID: 34800949 PMCID: PMC8598263 DOI: 10.1063/5.0072380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 10/28/2021] [Indexed: 11/15/2022] Open
Abstract
The description of each separable contribution of the intermolecular interaction is a useful approach to develop polarizable force fields (polFFs). The Gaussian Electrostatic Model (GEM) is based on this approach, coupled with the use of density fitting techniques. In this work, we present the implementation and testing of two improvements of GEM: the Coulomb and exchange-repulsion energies are now computed with separate frozen molecular densities and a new dispersion formulation inspired by the Sum of Interactions Between Fragments Ab initio Computed polFF, which has been implemented to describe the dispersion and charge-transfer interactions. Thanks to the combination of GEM characteristics and these new features, we demonstrate a better agreement of the computed structural and condensed properties for water with experimental results, as well as binding energies in the gas phase with the ab initio reference compared with the previous GEM* potential. This work provides further improvements to GEM and the items that remain to be improved and the importance of the accurate reproduction for each separate contribution.
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Affiliation(s)
- Sehr Naseem-Khan
- Department of Chemistry, University of North Texas, Denton, Texas 76201, USA
| | - Jean-Philip Piquemal
- Laboratoire de Chimie Théorique, Sorbonne Université, UMR 7616 CNRS, 75005 Paris, France
| | - G. Andrés Cisneros
- Department of Chemistry, University of North Texas, Denton, Texas 76201, USA
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