Analysis of solvation structure and thermodynamics of methane in water by reference interaction site model theory using an all-atom model

Abstract

An all-atom molecular model and optimized site–site pair potential parameters are employed for methane solute. By use of the reference interaction site model theory, the methane hydration structure is analyzed at the atomic level and its hydration free energies, energies, enthalpies, and entropies for four different thermodynamic states: temperature T=283.15, 298.15, 313.15, 328.15 K and the corresponding bulk water density ρ=0.9997, 0.9970, 0.9922, 0.9875 g cm−3 are calculated. Our calculated thermodynamic properties are in rather good agreement with experiments.