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Blazquez S, Abascal JLF, Lagerweij J, Habibi P, Dey P, Vlugt TJH, Moultos OA, Vega C. Computation of Electrical Conductivities of Aqueous Electrolyte Solutions: Two Surfaces, One Property. J Chem Theory Comput 2023; 19:5380-5393. [PMID: 37506381 PMCID: PMC10448725 DOI: 10.1021/acs.jctc.3c00562] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Indexed: 07/30/2023]
Abstract
In this work, we computed electrical conductivities under ambient conditions of aqueous NaCl and KCl solutions by using the Einstein-Helfand equation. Common force fields (charge q = ±1 e) do not reproduce the experimental values of electrical conductivities, viscosities, and diffusion coefficients. Recently, we proposed the idea of using different charges to describe the potential energy surface (PES) and the dipole moment surface (DMS). In this work, we implement this concept. The equilibrium trajectories required to evaluate electrical conductivities (within linear response theory) were obtained by using scaled charges (with the value q = ±0.75 e) to describe the PES. The potential parameters were those of the Madrid-Transport force field, which accurately describe viscosities and diffusion coefficients of these ionic solutions. However, integer charges were used to compute the conductivities (thus describing the DMS). The basic idea is that although the scaled charge describes the ion-water interaction better, the integer charge reflects the value of the charge that is transported due to the electric field. The agreement obtained with experiments is excellent, as for the first time electrical conductivities (and the other transport properties) of NaCl and KCl electrolyte solutions are described with high accuracy for the whole concentration range up to their solubility limit. Finally, we propose an easy way to obtain a rough estimate of the actual electrical conductivity of the potential model under consideration using the approximate Nernst-Einstein equation, which neglects correlations between different ions.
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Affiliation(s)
- Samuel Blazquez
- Dpto.
Química Física I, Fac. Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Jose L. F. Abascal
- Dpto.
Química Física I, Fac. Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Jelle Lagerweij
- Engineering
Thermodynamics, Process and Energy Department, Faculty of Mechanical,
Maritime and Materials Engineering, Delft
University of Technology, Leeghwaterstraat 39, 2628CB Delft, The Netherlands
| | - Parsa Habibi
- Engineering
Thermodynamics, Process and Energy Department, Faculty of Mechanical,
Maritime and Materials Engineering, Delft
University of Technology, Leeghwaterstraat 39, 2628CB Delft, The Netherlands
- Department
of Materials Science and Engineering, Faculty of Mechanical, Maritime
and Materials Engineering, Delft University
of Technology, Mekelweg
2, 2628CD Delft, The Netherlands
| | - Poulumi Dey
- Department
of Materials Science and Engineering, Faculty of Mechanical, Maritime
and Materials Engineering, Delft University
of Technology, Mekelweg
2, 2628CD Delft, The Netherlands
| | - Thijs J. H. Vlugt
- Engineering
Thermodynamics, Process and Energy Department, Faculty of Mechanical,
Maritime and Materials Engineering, Delft
University of Technology, Leeghwaterstraat 39, 2628CB Delft, The Netherlands
| | - Othonas A. Moultos
- Engineering
Thermodynamics, Process and Energy Department, Faculty of Mechanical,
Maritime and Materials Engineering, Delft
University of Technology, Leeghwaterstraat 39, 2628CB Delft, The Netherlands
| | - Carlos Vega
- Dpto.
Química Física I, Fac. Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
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2
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Blazquez S, Conde MM, Vega C. Scaled charges for ions: An improvement but not the final word for modeling electrolytes in water. J Chem Phys 2023; 158:054505. [PMID: 36754806 DOI: 10.1063/5.0136498] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
In this work, we discuss the use of scaled charges when developing force fields for NaCl in water. We shall develop force fields for Na+ and Cl- using the following values for the scaled charge (in electron units): ±0.75, ±0.80, ±0.85, and ±0.92 along with the TIP4P/2005 model of water (for which previous force fields were proposed for q = ±0.85 and q = ±1). The properties considered in this work are densities, structural properties, transport properties, surface tension, freezing point depression, and maximum in density. All the developed models were able to describe quite well the experimental values of the densities. Structural properties were well described by models with charges equal to or larger than ±0.85, surface tension by the charge ±0.92, maximum in density by the charge ±0.85, and transport properties by the charge ±0.75. The use of a scaled charge of ±0.75 is able to reproduce with high accuracy the viscosities and diffusion coefficients of NaCl solutions for the first time. We have also considered the case of KCl in water, and the results obtained were fully consistent with those of NaCl. There is no value of the scaled charge able to reproduce all the properties considered in this work. Although certainly scaled charges are not the final word in the development of force fields for electrolytes in water, its use may have some practical advantages. Certain values of the scaled charge could be the best option when the interest is to describe certain experimental properties.
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Affiliation(s)
- S Blazquez
- Dpto. Química Física I, Fac. Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - M M Conde
- Departamento de Ingeniería Química Industrial y Medio Ambiente, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid, 28006 Madrid, Spain
| | - C Vega
- Dpto. Química Física I, Fac. Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
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3
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Building a Hofmeister-like series for the maximum in density temperature of aqueous electrolyte solutions. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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4
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Sedano LF, Blazquez S, Noya EG, Vega C, Troncoso J. Maximum in density of electrolyte solutions: Learning about ion-water interactions and testing the Madrid-2019 force field. J Chem Phys 2022; 156:154502. [PMID: 35459318 DOI: 10.1063/5.0087679] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this work, we studied the effect of Li+, Na+, K+, Mg2+, and Ca2+ chlorides and sulfates on the temperature of maximum density (TMD) of aqueous solutions at room pressure. Experiments at 1 molal salt concentration were carried out to determine the TMD of these solutions. We also performed molecular dynamics simulations to estimate the TMD at 1 and 2 m with the Madrid-2019 force field, which uses the TIP4P/2005 water model and scaled charges for the ions, finding an excellent agreement between experiment and simulation. All the salts studied in this work shift the TMD of the solution to lower temperatures and flatten the density vs temperature curves (when compared to pure water) with increasing salt concentration. The shift in the TMD depends strongly on the nature of the electrolyte. In order to explore this dependence, we have evaluated the contribution of each ion to the shift in the TMD concluding that Na+, Ca2+, and SO4 2- seem to induce the largest changes among the studied ions. The volume of the system has been analyzed for salts with the same anion and different cations. These curves provide insight into the effect of different ions upon the structure of water. We claim that the TMD of electrolyte solutions entails interesting physics regarding ion-water and water-water interactions and should, therefore, be considered as a test property when developing force fields for electrolytes. This matter has been rather unnoticed for almost a century now and we believe it is time to revisit it.
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Affiliation(s)
- L F Sedano
- Depto. Química Física I (Unidad Asociada de I+D+i al CSIC), Fac. Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - S Blazquez
- Depto. Química Física I (Unidad Asociada de I+D+i al CSIC), Fac. Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - E G Noya
- Instituto de Química Física Rocasolano, Consejo Superior de Investigaciones Científicas, CSIC, Calle Serrano 119, 28006 Madrid, Spain
| | - C Vega
- Depto. Química Física I (Unidad Asociada de I+D+i al CSIC), Fac. Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - J Troncoso
- Departamento de Física Aplicada, Universidad de Vigo, Facultad de Ciencias del Campus de Ourense, E 32004 Ourense, Spain
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5
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Blazquez S, Conde MM, Abascal JLF, Vega C. The Madrid-2019 force field for electrolytes in water using TIP4P/2005 and scaled charges: Extension to the ions F−, Br−, I−, Rb+, and Cs+. J Chem Phys 2022; 156:044505. [DOI: 10.1063/5.0077716] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- S. Blazquez
- Departamento Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - M. M. Conde
- Departamento de Ingeniería Química Industrial y Medio Ambiente, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid, 28006 Madrid, Spain
| | - J. L. F. Abascal
- Departamento Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - C. Vega
- Departamento Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
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6
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Berkowitz ML. Molecular Simulations of Aqueous Electrolytes: Role of Explicit Inclusion of Charge Transfer into Force Fields. J Phys Chem B 2021; 125:13069-13076. [PMID: 34807628 DOI: 10.1021/acs.jpcb.1c08383] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe here simulations of aqueous salt solutions that are performed using an explicit charge transfer force field. The emphasis of the discussion is on the calculation of a dynamical property of the solutions: self-diffusion of water. While force fields that are based on pairwise additive potentials or on potentials with explicit inclusion of polarization or with scaled charges can provide at best a qualitative agreement with experiments, force fields with explicit inclusion of charge transfer can produce quantitative agreement with experiment for NaCl and KCl solutions. We argue that a force field with explicit charge transfer contains new physics absent in the previously used force fields described in recent reviews of molecular simulations of aqueous electrolytes.
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Affiliation(s)
- Max L Berkowitz
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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7
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Gundelach L, Fox T, Tautermann CS, Skylaris CK. Protein–ligand free energies of binding from full-protein DFT calculations: convergence and choice of exchange–correlation functional. Phys Chem Chem Phys 2021; 23:9381-9393. [DOI: 10.1039/d1cp00206f] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Quantum mechanical binding free energies based on thousands of full-protein DFT calculations are tractable, reproducible and converge well.
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Affiliation(s)
- Lennart Gundelach
- University of Southampton Faculty of Engineering Science and Mathematics, Chemistry
- University Road
- Southampton
- UK
| | - Thomas Fox
- Boehringer Ingelheim Pharma GmbH & Co KG
- Medicinal Chemistry
- 88397 Biberach an der Riss
- Germany
| | | | - Chris-Kriton Skylaris
- University of Southampton Faculty of Engineering Science and Mathematics, Chemistry
- University Road
- Southampton
- UK
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8
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Charge transfer as a ubiquitous mechanism in determining the negative charge at hydrophobic interfaces. Nat Commun 2020; 11:901. [PMID: 32060273 PMCID: PMC7021814 DOI: 10.1038/s41467-020-14659-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 01/22/2020] [Indexed: 01/17/2023] Open
Abstract
The origin of the apparent negative charge at hydrophobic–water interfaces has fueled debates in the physical chemistry community for decades. The most common interpretation given to explain this observation is that negatively charged hydroxide ions (OH–) bind strongly to the interfaces. Using first principles calculations of extended air–water and oil–water interfaces, we unravel a mechanism that does not require the presence of OH–. Small amounts of charge transfer along hydrogen bonds and asymmetries in the hydrogen bond network due to topological defects can lead to the accumulation of negative surface charge at both interfaces. For water near oil, some spillage of electron density into the oil phase is also observed. The computed surface charge densities at both interfaces is approximately \documentclass[12pt]{minimal}
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\setlength{\oddsidemargin}{-69pt}
\begin{document}$$-0.015\ {\rm{e}}/{{\rm{nm}}}^{2}$$\end{document}−0.015e∕nm2 in agreement with electrophoretic experiments. We also show, using an energy decomposition analysis, that the electronic origin of this phenomena is rooted in a collective polarization/charge transfer effect. The accumulation of negative charge at hydrophobic–water interfaces has been a source of debate for a long time. Here the authors use ab initio calculations to show that the charge accumulation at air–water and oil–water interfaces is caused by subtle charge transfer processes.
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9
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Schröder C, Lyons A, Rick SW. Polarizable MD simulations of ionic liquids: How does additional charge transfer change the dynamics? Phys Chem Chem Phys 2020; 22:467-477. [DOI: 10.1039/c9cp05478b] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new model for treating charge transfer in ionic liquids is developed and applied to 1-ethyl-3-methylimidazolium tetrafluoroborate. The model allows for us to examine the roles of charge transfer, polarizability, and charge scaling effects on the dynamics of ionic liquids.
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Affiliation(s)
- Christian Schröder
- University of Vienna
- Faculty of Chemistry
- Department of Computational Biological Chemistry
- A-1090 Vienna
- Austria
| | - Alex Lyons
- University of New Orleans
- Department of Chemistry
- New Orleans
- USA
| | - Steven W. Rick
- University of New Orleans
- Department of Chemistry
- New Orleans
- USA
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10
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Li M, Lu Y, An L. Ion Polarizabilities in Binary Liquid Mixtures of Water/Organic Solvents. J Phys Chem B 2018; 122:10023-10030. [DOI: 10.1021/acs.jpcb.8b07327] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Minglun Li
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Yuyuan Lu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People’s Republic of China
| | - Lijia An
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People’s Republic of China
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11
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Nguyen M, Rick SW. The influence of polarizability and charge transfer on specific ion effects in the dynamics of aqueous salt solutions. J Chem Phys 2018; 148:222803. [PMID: 29907071 DOI: 10.1063/1.5012682] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The diffusion rates for water molecules in salt solutions depend on the identity of the ions, as well as their concentration. Among the alkali metal ions, cesium and potassium increase and sodium strongly decreases the diffusion constant of water. The origin of the difference can be understood by examining the simulation results using different potential models. In this work, aqueous solutions of salts are simulated with a variety of models. Commonly used non-polarizable models, which otherwise reproduce many experimental properties, do not capture the trend in the diffusion constant, while models which include polarization and/or charge transfer interactions do. For the non-polarizable models, the diffusion constant decreases too strongly with salt concentration. The changes in the water diffusion constant with increasing salt concentration match the diffusion constant of the ion. The ion diffusion constant is dependent on the residence time for water in the ion solvation shell. The non-polarizable models over-estimate the residence time, relative to the translational diffusion constant and so tend to under-estimate the ion and water diffusion constants.
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Affiliation(s)
- Mary Nguyen
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, USA
| | - Steven W Rick
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, USA
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12
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Demerdash O, Mao Y, Liu T, Head-Gordon M, Head-Gordon T. Assessing many-body contributions to intermolecular interactions of the AMOEBA force field using energy decomposition analysis of electronic structure calculations. J Chem Phys 2018; 147:161721. [PMID: 29096520 DOI: 10.1063/1.4999905] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this work, we evaluate the accuracy of the classical AMOEBA model for representing many-body interactions, such as polarization, charge transfer, and Pauli repulsion and dispersion, through comparison against an energy decomposition method based on absolutely localized molecular orbitals (ALMO-EDA) for the water trimer and a variety of ion-water systems. When the 2- and 3-body contributions according to the many-body expansion are analyzed for the ion-water trimer systems examined here, the 3-body contributions to Pauli repulsion and dispersion are found to be negligible under ALMO-EDA, thereby supporting the validity of the pairwise-additive approximation in AMOEBA's 14-7 van der Waals term. However AMOEBA shows imperfect cancellation of errors for the missing effects of charge transfer and incorrectness in the distance dependence for polarization when compared with the corresponding ALMO-EDA terms. We trace the larger 2-body followed by 3-body polarization errors to the Thole damping scheme used in AMOEBA, and although the width parameter in Thole damping can be changed to improve agreement with the ALMO-EDA polarization for points about equilibrium, the correct profile of polarization as a function of intermolecular distance cannot be reproduced. The results suggest that there is a need for re-examining the damping and polarization model used in the AMOEBA force field and provide further insights into the formulations of polarizable force fields in general.
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Affiliation(s)
- Omar Demerdash
- Departments of Chemistry, University of California, Berkeley, California 94720, USA
| | - Yuezhi Mao
- Departments of Chemistry, University of California, Berkeley, California 94720, USA
| | - Tianyi Liu
- Departments of Chemistry, University of California, Berkeley, California 94720, USA
| | - Martin Head-Gordon
- Departments of Chemistry, University of California, Berkeley, California 94720, USA
| | - Teresa Head-Gordon
- Departments of Chemistry, University of California, Berkeley, California 94720, USA
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13
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Ahlstrand E, Zukerman Schpector J, Friedman R. Computer simulations of alkali-acetate solutions: Accuracy of the forcefields in difference concentrations. J Chem Phys 2018; 147:194102. [PMID: 29166095 DOI: 10.1063/1.4985919] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
When proteins are solvated in electrolyte solutions that contain alkali ions, the ions interact mostly with carboxylates on the protein surface. Correctly accounting for alkali-carboxylate interactions is thus important for realistic simulations of proteins. Acetates are the simplest carboxylates that are amphipathic, and experimental data for alkali acetate solutions are available and can be compared with observables obtained from simulations. We carried out molecular dynamics simulations of alkali acetate solutions using polarizable and non-polarizable forcefields and examined the ion-acetate interactions. In particular, activity coefficients and association constants were studied in a range of concentrations (0.03, 0.1, and 1M). In addition, quantum-mechanics (QM) based energy decomposition analysis was performed in order to estimate the contribution of polarization, electrostatics, dispersion, and QM (non-classical) effects on the cation-acetate and cation-water interactions. Simulations of Li-acetate solutions in general overestimated the binding of Li+ and acetates. In lower concentrations, the activity coefficients of alkali-acetate solutions were too high, which is suggested to be due to the simulation protocol and not the forcefields. Energy decomposition analysis suggested that improvement of the forcefield parameters to enable accurate simulations of Li-acetate solutions can be achieved but may require the use of a polarizable forcefield. Importantly, simulations with some ion parameters could not reproduce the correct ion-oxygen distances, which calls for caution in the choice of ion parameters when protein simulations are performed in electrolyte solutions.
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Affiliation(s)
- Emma Ahlstrand
- Department of Chemistry and Biomedical Sciences, Linnæus University, 391 82 Kalmar, Sweden
| | - Julio Zukerman Schpector
- Universidade Federal de São Carlos, Departamento de Química, CP 676, 13565-905 São Carlos, SP, Brazil
| | - Ran Friedman
- Department of Chemistry and Biomedical Sciences, Linnæus University, 391 82 Kalmar, Sweden
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14
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Albaugh A, Boateng HA, Bradshaw RT, Demerdash ON, Dziedzic J, Mao Y, Margul DT, Swails J, Zeng Q, Case DA, Eastman P, Wang LP, Essex JW, Head-Gordon M, Pande VS, Ponder JW, Shao Y, Skylaris CK, Todorov IT, Tuckerman ME, Head-Gordon T. Advanced Potential Energy Surfaces for Molecular Simulation. J Phys Chem B 2018; 120:9811-32. [PMID: 27513316 DOI: 10.1021/acs.jpcb.6b06414] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Advanced potential energy surfaces are defined as theoretical models that explicitly include many-body effects that transcend the standard fixed-charge, pairwise-additive paradigm typically used in molecular simulation. However, several factors relating to their software implementation have precluded their widespread use in condensed-phase simulations: the computational cost of the theoretical models, a paucity of approximate models and algorithmic improvements that can ameliorate their cost, underdeveloped interfaces and limited dissemination in computational code bases that are widely used in the computational chemistry community, and software implementations that have not kept pace with modern high-performance computing (HPC) architectures, such as multicore CPUs and modern graphics processing units (GPUs). In this Feature Article we review recent progress made in these areas, including well-defined polarization approximations and new multipole electrostatic formulations, novel methods for solving the mutual polarization equations and increasing the MD time step, combining linear-scaling electronic structure methods with new QM/MM methods that account for mutual polarization between the two regions, and the greatly improved software deployment of these models and methods onto GPU and CPU hardware platforms. We have now approached an era where multipole-based polarizable force fields can be routinely used to obtain computational results comparable to state-of-the-art density functional theory while reaching sampling statistics that are acceptable when compared to that obtained from simpler fixed partial charge force fields.
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Affiliation(s)
| | - Henry A Boateng
- Department of Mathematics, Bates College , 2 Andrews Road, Lewiston, Maine 04240, United States
| | - Richard T Bradshaw
- School of Chemistry, University of Southampton , Highfield, Southampton SO17 1BJ, United Kingdom
| | | | - Jacek Dziedzic
- School of Chemistry, University of Southampton , Highfield, Southampton SO17 1BJ, United Kingdom.,Faculty of Applied Physics and Mathematics, Gdansk University of Technology , 80-223 Gdansk, Poland
| | | | | | - Jason Swails
- Department of Chemistry and Chemical Biology, Rutgers University , Piscataway, New Jersey 08854-8066, United States
| | - Qiao Zeng
- Laboratory of Computational Biology, National Heart, Lung and Blood Institute, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - David A Case
- Department of Chemistry and Chemical Biology, Rutgers University , Piscataway, New Jersey 08854-8066, United States
| | - Peter Eastman
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
| | - Lee-Ping Wang
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
| | - Jonathan W Essex
- School of Chemistry, University of Southampton , Highfield, Southampton SO17 1BJ, United Kingdom
| | | | - Vijay S Pande
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
| | - Jay W Ponder
- Department of Chemistry, Washington University in St. Louis , St. Louis, Missouri 63130, United States
| | - Yihan Shao
- Q-Chem Inc. , 6601 Owens Drive, Suite 105, Pleasanton, California 94588, United States
| | - Chris-Kriton Skylaris
- School of Chemistry, University of Southampton , Highfield, Southampton SO17 1BJ, United Kingdom
| | - Ilian T Todorov
- STFC Daresbury Laboratory , Keckwick Lane, Daresbury, Warrington WA4 4AD, United Kingdom
| | - Mark E Tuckerman
- NYU-ECNU, Center for Computational Chemistry at NYU, Shanghai , Shanghai 200062, China
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15
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Esser A, Belsare S, Marx D, Head-Gordon T. Mode specific THz spectra of solvated amino acids using the AMOEBA polarizable force field. Phys Chem Chem Phys 2018; 19:5579-5590. [PMID: 28165073 DOI: 10.1039/c6cp07388c] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have used the AMOEBA model to simulate the THz spectra of two zwitterionic amino acids in aqueous solution, which is compared to the results on these same systems using ab initio molecular dynamics (AIMD) simulations. Overall we find that the polarizable force field shows promising agreement with AIMD data for both glycine and valine in water. This includes the THz spectral assignments and the mode-specific spectral decomposition into intramolecular solute motions as well as distinct solute-water cross-correlation modes some of which cannot be captured by non-polarizable force fields that rely on fixed partial charges. This bodes well for future studies for simulating and decomposing the THz spectra for larger solutes such as proteins or polymers for which AIMD studies are presently intractable. Furthermore, we believe that the current study on rather simple aqueous solutions offers a way to systematically investigate the importance of charge transfer, nuclear quantum effects, and the validity of computationally practical density functionals, all of which are needed to fully quantitatively capture complex dynamical motions in the condensed phase.
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Affiliation(s)
- Alexander Esser
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany.
| | - Saurabh Belsare
- The UC Berkeley - UCSF Graduate Program in Bioengineering, University of California, Berkeley, CA, 94720, USA
| | - Dominik Marx
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany.
| | - Teresa Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, Department of Bioengineering, Department of Chemical and Biomolecular Engineering, University of California Berkeley, CA 94720, USA.
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16
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Li M, Zhuang B, Lu Y, Wang ZG, An L. Accurate Determination of Ion Polarizabilities in Aqueous Solutions. J Phys Chem B 2017; 121:6416-6424. [PMID: 28594180 DOI: 10.1021/acs.jpcb.7b04111] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present a novel method for obtaining salt polarizabilities in aqueous solutions based on our recent theory for the refractive index of salt solutions, which predicts a linear relationship between the refractive index and the salt concentration at low concentrations, with a slope determined by the intrinsic values of the salt polarizability and the density of the solution. Here we apply this theory to determine the polarizabilities of 32 strong electrolyte salts in aqueous solutions from refractive index and density measurements. Setting Li+ as the standard ion, we then determine the polarizabilities of seven cations (Na+, K+, Rb+, Cs+, Ca2+, Ba2+, and Sr2+) and seven anions (F-, Cl-, Br-, I-, ClO4-, NO3-, and SO42-), which can be used as important reference data. We investigate the effect of temperature on salt polarizabilities, which decreases slightly with increasing temperature. The ion polarizability is found to be proportional to the cube of bare ionic radius (rbare3) for univalent ions, but the relationship does not hold for multivalent ions. Contrary to findings of Krishnamurti, we find no significant linear relationship between ion polarizability and the square of the atomic number (N2) for smaller ions.
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Affiliation(s)
- Minglun Li
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, People's Republic of China.,University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China
| | - Bilin Zhuang
- Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States
| | - Yuyuan Lu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, People's Republic of China
| | - Zhen-Gang Wang
- Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States
| | - Lijia An
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, People's Republic of China
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17
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Mao Y, Demerdash O, Head-Gordon M, Head-Gordon T. Assessing Ion-Water Interactions in the AMOEBA Force Field Using Energy Decomposition Analysis of Electronic Structure Calculations. J Chem Theory Comput 2016; 12:5422-5437. [PMID: 27709939 DOI: 10.1021/acs.jctc.6b00764] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AMOEBA is a molecular mechanics force field that addresses some of the shortcomings of a fixed partial charge model, by including permanent atomic point multipoles through quadrupoles, as well as many-body polarization through the use of point inducible dipoles. In this work, we investigate how well AMOEBA formulates its non-bonded interactions, and how it implicitly incorporates quantum mechanical effects such as charge penetration (CP) and charge transfer (CT), for water-water and water-ion interactions. We find that AMOEBA's total interaction energies, as a function of distance and over angular scans for the water dimer and for a range of water-monovalent cations, agree well with an advanced density functional theory (DFT) model, whereas the water-halides and water-divalent cations show significant disagreement with the DFT result, especially in the compressed region when the two fragments overlap. We use a second-generation energy decomposition analysis (EDA) scheme based on absolutely localized molecular orbitals (ALMOs) to show that in the best cases AMOEBA relies on cancellation of errors by softening of the van der Waals (vdW) wall to balance permanent electrostatics that are too unfavorable, thereby compensating for the missing CP effect. CT, as another important stabilizing effect not explicitly taken into account in AMOEBA, is also found to be incorporated by the softened vdW interaction. For the water-halides and water-divalent cations, this compensatory approach is not as well executed by AMOEBA over all distances and angles, wherein permanent electrostatics remains too unfavorable and polarization is overdamped in the former while overestimated in the latter. We conclude that the DFT-based EDA approach can help refine a next-generation AMOEBA model that either realizes a better cancellation of errors for problematic cases like those illustrated here, or serves to guide the parametrization of explicit functional forms for short-range contributions from CP and/or CT.
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Affiliation(s)
- Yuezhi Mao
- Kenneth S. Pitzer Center for Theoretical Chemistry, and Department of Chemistry, University of California at Berkeley , Berkeley, California 94720, United States
| | - Omar Demerdash
- Kenneth S. Pitzer Center for Theoretical Chemistry, and Department of Chemistry, University of California at Berkeley , Berkeley, California 94720, United States
| | - Martin Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry, and Department of Chemistry, University of California at Berkeley , Berkeley, California 94720, United States
| | - Teresa Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry, and Department of Chemistry, University of California at Berkeley , Berkeley, California 94720, United States.,Department of Bioengineering, and Department of Chemical and Biomolecular Engineering, University of California at Berkeley , Berkeley, California 94720, United States
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18
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Rick SW. A polarizable, charge transfer model of water using the drude oscillator. J Comput Chem 2016; 37:2060-6. [DOI: 10.1002/jcc.24426] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 04/14/2016] [Accepted: 05/17/2016] [Indexed: 12/24/2022]
Affiliation(s)
- Steven W. Rick
- Department of ChemistryUniversity of New OrleansNew Orleans70148 Los Angeles
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19
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Ou SC, Cui D, Patel S. Molecular modeling of ions at interfaces: exploring similarities to hydrophobic solvation through the lens of induced aqueous interfacial fluctuations. Phys Chem Chem Phys 2016; 18:30357-30365. [DOI: 10.1039/c6cp04112d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ion specific effects are ubiquitous in chemistry and biology.
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Affiliation(s)
- Shu-Ching Ou
- Sealy Center for Structural Biology and Molecular Biophysics
- University of Texas Medical Branch
- 301 University Boulevard
- Galveston
- USA
| | - Di Cui
- Department of Chemistry
- Temple University
- Philadelphia
- USA
| | - Sandeep Patel
- Department of Chemistry and Biochemistry
- University of Delaware
- Newark
- USA
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20
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Yao Y, Berkowitz ML, Kanai Y. Communication: Modeling of concentration dependent water diffusivity in ionic solutions: Role of intermolecular charge transfer. J Chem Phys 2015; 143:241101. [DOI: 10.1063/1.4938083] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Yi Yao
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Max L. Berkowitz
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Yosuke Kanai
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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21
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Soniat M, Kumar R, Rick SW. Hydrated proton and hydroxide charge transfer at the liquid/vapor interface of water. J Chem Phys 2015; 143:044702. [DOI: 10.1063/1.4926831] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Marielle Soniat
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, USA
| | - Revati Kumar
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70808, USA
| | - Steven W. Rick
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, USA
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22
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Shultz MJ, Bisson P, Vu TH. Insights into hydrogen bonding via ice interfaces and isolated water. J Chem Phys 2015; 141:18C521. [PMID: 25399186 DOI: 10.1063/1.4896603] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Water in a confined environment has a combination of fewer available configurations and restricted mobility. Both affect the spectroscopic signature. In this work, the spectroscopic signature of water in confined environments is discussed in the context of competing models for condensed water: (1) as a system of intramolecular coupled molecules or (2) as a network with intermolecular dipole-dipole coupled O-H stretches. Two distinct environments are used: the confined asymmetric environment at the ice surface and the near-isolated environment of water in an infrared transparent matrix. Both the spectroscopy and the environment are described followed by a perspective discussion of implications for the two competing models. Despite being a small molecule, water is relatively complex; perhaps not surprisingly the results support a model that blends inter- and intramolecular coupling. The frequency, and therefore the hydrogen-bond strength, appears to be a function of donor-acceptor interaction and of longer-range dipole-dipole alignment in the hydrogen-bonded network. The O-H dipole direction depends on the local environment and reflects intramolecular O-H stretch coupling.
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Affiliation(s)
- Mary Jane Shultz
- Laboratory for Water and Surface Studies, Chemistry Department, Tufts University, Medford, Massachusetts 02155, USA
| | - Patrick Bisson
- Laboratory for Water and Surface Studies, Chemistry Department, Tufts University, Medford, Massachusetts 02155, USA
| | - Tuan Hoang Vu
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109, USA
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23
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Pezeshki S, Lin H. Adaptive-Partitioning QM/MM for Molecular Dynamics Simulations: 4. Proton Hopping in Bulk Water. J Chem Theory Comput 2015; 11:2398-411. [DOI: 10.1021/ct501019y] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Soroosh Pezeshki
- Chemistry Department, University of Colorado Denver, Denver, Colorado 80217-3364, United States
| | - Hai Lin
- Chemistry Department, University of Colorado Denver, Denver, Colorado 80217-3364, United States
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24
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Torii H. Electronic Structural Basis for the Atomic Partial Charges of Planar Molecular Systems Derived from Out-of-Plane Dipole Derivatives. J Phys Chem A 2015; 119:3277-84. [DOI: 10.1021/jp512884g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hajime Torii
- Department
of Chemistry,
Faculty of Education, and Department of Optoelectronics and Nanostructure
Science, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Shizuoka 422-8529, Japan
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25
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Soniat M, Hartman L, Rick SW. Charge Transfer Models of Zinc and Magnesium in Water. J Chem Theory Comput 2015; 11:1658-67. [DOI: 10.1021/ct501173n] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Marielle Soniat
- Department
of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, United States
| | - Lisa Hartman
- Benjamin Franklin High School, New Orleans, Louisiana 70122, United States
| | - Steven W. Rick
- Department
of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, United States
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26
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Ou SC, Cui D, Patel S. Association of alkanes with the aqueous liquid-vapor interface: a reference system for interpreting hydrophobicity generally through interfacial fluctuations. Phys Chem Chem Phys 2014; 16:26779-85. [PMID: 25372502 DOI: 10.1039/c4cp03170a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report free energy calculations and fluctuation profiles of single alkanes (from methane to pentane) along the direction normal to the air-water interface. The induced fluctuations and the interfacial stabilities of alkanes are found to be correlated and similar to the results of inorganic monovalent ions (Ou et al., J. Phys. Chem. B, 2013, 117, 11732). This suggests that hydrophobic solvation of solutes and ions is important in determining the adsorption behavior.
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Affiliation(s)
- Shu-Ching Ou
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
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27
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Yao Y, Kanai Y, Berkowitz ML. Role of Charge Transfer in Water Diffusivity in Aqueous Ionic Solutions. J Phys Chem Lett 2014; 5:2711-2716. [PMID: 26277968 DOI: 10.1021/jz501238v] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We performed molecular dynamics simulations on four types of systems containing ion and solvating water. Two systems contained a cation (Na(+) or K(+)), and two other systems an anion (Cl(-) or I(-)). Classical molecular dynamics simulations were performed using three different force fields: a fixed charge force field, a polarizable force field that includes explicit polarization, and also a recently developed force field that includes polarization and charge transfer. These simulations were then compared to first-principles molecular dynamics simulations. While the first-principles simulations showed that the anions accelerated water translational diffusion, the cations slowed it down. In simulations with the classical force fields, only the force field that incorporates explicit charge transfer reproduced this ion-specific behavior. Additional simulations performed to understand the effect of charge transfer demonstrated that two competitive factors determine the behavior of water translational diffusion: the ions diminished charge accelerates water, while the net charge acquired by water either accelerates or slows down its dynamics. Our results show that charge transfer plays a crucial role in governing the water dynamics in aqueous ionic solutions.
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Affiliation(s)
- Yi Yao
- †Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Yosuke Kanai
- †Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- ‡Condensed Matter and Materials Division, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Max L Berkowitz
- †Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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