Evaluating performance of the approximate 3D-RISM-KH molecular solvation theory for solvation free energies in alkanes and alkane-water partition coefficients

Abstract

The performance of the 3D-reference interaction site model (3D-RISM) with the Kovalenko-Hirata (KH) closure is benchmarked for liquid alkanes. The liquids are modelled using the united atom formalism. The intermolecular distribution functions obtained from the computations are in good agreement with the experimental reports. The solvation free energy (SFE) computed in the alkanes for a large set of solutes also agrees well with the experimental data. The molecular partition coefficients for alkane-water partition of the compounds were calculated for cyclohexane-water, alkane-water, and hexadecane-water partitions of a total of eight hundred and forty-three organic compounds with reliable accuracy. A calibration scale is proposed for alkane-water partition coefficient calculations based on the 3D-RISM-KH theory.