Solvation free energies of methane and alkali halide ion pairs: An expanded ensemble molecular dynamics simulation study

Solvation free energy for methane, dissolved both in pure water, water/methane mixture (14 mol % methane) and in aqueous NaCl solution, is calculated using the expanded ensemble molecular dynamics method. Dependencies due to system size and potential model are investigated. Results, using a simple one-site methane model, together with large enough system size, are found in very good agreement with experimental data, while calculations using a flexible five-site methane model give too high free energies. Also, the solvation energy for 20 different ion pairs of alkali halides is calculated in a systematic study. Very good overall agreement is found for the solvation energies of all the ion pairs. Calculations of solvation free energies provide a sensitive test of the used potential models.

[1]  D. Frenkel,et al.  Unexpected length dependence of the solubility of chain molecules , 1992 .

[2]  Y. Guissani,et al.  A computer‐simulation study of hydrophobic hydration of rare gases and of methane. I. Thermodynamic and structural properties , 1991 .

[3]  Alexander P. Lyubartsev,et al.  Determination of Free Energy from Chemical Potentials: Application of the Expanded Ensemble Method , 1996 .

[4]  William L. Jorgensen,et al.  Free energy of TIP4P water and the free energies of hydration of CH4 and Cl- from statistical perturbation theory , 1989 .

[5]  Peter A. Kollman,et al.  Simulation of the solvation free energies for methane, ethane, and propane and corresponding amino acid dipeptides : a critical test of the bond-PMF correction, a new set of hydrocarbon parameters, and the gas phase-water hydrophobicity scale , 1992 .

[6]  Peter A. Kollman,et al.  The lag between the Hamiltonian and the system configuration in free energy perturbation calculations , 1989 .

[7]  Mark E. Tuckerman,et al.  Reversible multiple time scale molecular dynamics , 1992 .

[8]  A D Bruce,et al.  A study of the multi-canonical Monte Carlo method , 1995 .

[9]  Nigel B. Wilding,et al.  Accurate measurements of the chemical potential of polymeric systems by Monte Carlo simulation , 1994 .

[10]  Shuichi Nosé,et al.  Constant-temperature molecular dynamics , 1990 .

[11]  A. Laaksonen,et al.  Molecular dynamics and NMR study of methane-water systems , 1991 .

[12]  R. Wood.  Continuum electrostatics in a computational universe with finite cutoff radii and periodic boundary conditions: Correction to computed free energies of ionic solvation , 1995 .

[13]  Hoover,et al.  Canonical dynamics: Equilibrium phase-space distributions. , 1985, Physical review. A, General physics.

[14]  Hansmann,et al.  Monte Carlo simulations in generalized ensemble: Multicanonical algorithm versus simulated tempering. , 1996, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[15]  S. Nosé.  A molecular dynamics method for simulations in the canonical ensemble , 1984 .

[16]  Arieh Ben-Naim,et al.  Solvation thermodynamics of nonionic solutes , 1984 .

[17]  A. Lyubartsev,et al.  Calculation of effective interaction potentials from radial distribution functions: A reverse Monte Carlo approach. , 1995, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[18]  S. Kalko,et al.  On the effects of truncating the electrostatic interactions: Free energies of ion hydration , 1996 .

[19]  P. Kollman,et al.  Molecular dynamics free energy simulations: Influence of the truncation of long‐range nonbonded electrostatic interactions on free energy calculations of polar molecules , 1994 .

[20]  A. Lyubartsev,et al.  New approach to Monte Carlo calculation of the free energy: Method of expanded ensembles , 1992 .

[21]  K. Heinzinger.  Computer simulations of aqueous electrolyte solutions , 1985 .

[22]  P. Kollman,et al.  An all atom force field for simulations of proteins and nucleic acids , 1986, Journal of computational chemistry.

[23]  Gerhard Hummer,et al.  Free Energy of Ionic Hydration , 1996 .

[24]  Alexander P. Lyubartsev,et al.  Free energy calculations for Lennard-Jones systems and water using the expanded ensemble method A Monte Carlo and molecular dynamics simulation study , 1994 .

[25]  B. Berg,et al.  Multicanonical algorithms for first order phase transitions , 1991 .

[26]  G. Torrie,et al.  Nonphysical sampling distributions in Monte Carlo free-energy estimation: Umbrella sampling , 1977 .

[27]  K. Shing,et al.  The chemical potential from computer simulation , 1981 .

[28]  William L. Jorgensen,et al.  Optimized intermolecular potential functions for liquid hydrocarbons , 1984 .

[29]  B. Widom,et al.  Some Topics in the Theory of Fluids , 1963 .

[30]  G. Parisi,et al.  Simulated tempering: a new Monte Carlo scheme , 1992, hep-lat/9205018.

[31]  Juan J. de Pablo,et al.  Monte Carlo simulation of the chemical potential of polymers in an expanded ensemble , 1995 .

[32]  T. Straatsma,et al.  Free energy of ionic hydration: Analysis of a thermodynamic integration technique to evaluate free energy differences by molecular dynamics simulations , 1988 .

[33]  Ivo Nezbeda,et al.  A New Version of the Insertion Particle Method for Determining the Chemical Potential by Monte Carlo Simulation , 1991 .

[34]  C. Brooks.  Computer simulation of liquids , 1989 .

[35]  Carolyn A. Koh,et al.  Clathrate hydrates of natural gases , 1990 .

[36]  A. Martsinovski,et al.  A New Monte Carlo Method for Direct Calculation of the Critical Size and the Formation Work of a Microdrop , 1990 .

[37]  Yizhak Marcus,et al.  Thermodynamics of solvation of ions. Part 5.—Gibbs free energy of hydration at 298.15 K , 1991 .

[38]  T. Straatsma,et al.  Free energy of hydrophobic hydration: A molecular dynamics study of noble gases in water , 1986 .

[39]  Rahman,et al.  Molecular-dynamics study of atomic motions in water. , 1985, Physical review. B, Condensed matter.

[40]  J. P. Valleau,et al.  Umbrella‐sampling realization of ‘‘Widom’’ chemical potential estimation , 1993 .

[41]  P. A. Bash,et al.  Free energy calculations by computer simulation. , 1987, Science.

[42]  P. Attard.  Simulation of the chemical potential and the cavity free energy of dense hard‐sphere fluids , 1993 .

[43]  Peter A. Kollman,et al.  The overlooked bond‐stretching contribution in free energy perturbation calculations , 1991 .