Solvation free-energy pressure corrections in the three dimensional reference interaction site model

Volodymyr Sergiievskyi (1) , Guillaume Jeanmairet (2) , Maximilien Levesque (3) , Daniel Borgis (4, 5)

1 Universität Duisburg-Essen = University of Duisburg-Essen [Essen]
2 Max Planck Institute for Solid State Research
3 PASTEUR - Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640)
4 MDLS - Maison de la Simulation
5 PASTEUR - Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640)

Solvation free energies are efficiently predicted by molecular density functionnal the-ory (MDFT) if one corrects the overpressure introduced by the usual homogeneousreference fluid approximation. Sergiievskyi et al. [Sergiievskyi et al., JPCL, 2014,5, 1935-1942] recently derived the rigorous compensation of this excess of pressure(PC) and proposed an empirical ”ideal gas” supplementary correction (PC+) thatfurther enhances the calculated solvation free energies. In a recent paper [Misin etal, JCP, 2015, 142, 091105], those corrections were applied to solvation free energycalculations using the three-dimensional reference interaction site model (3D-RISM).As for classical DFT, PC and PC+ corrections improve greatly the predictions of3D-RISM, but PC+ is described as decreasing the accuracy. In this article, we de-rive rigorously the expression of the pressure in 3D-RISM as well as the associatedPC and PC+ corrections. This provides a consistent way to correct the solvationfree-energies calculated by 3D-RISM method.

Domaines: Chimie théorique et/ou physique

Volodymyr Sergiievskyi, Guillaume Jeanmairet, Maximilien Levesque, Daniel Borgis. Solvation free-energy pressure corrections in the three dimensional reference interaction site model. Journal of Chemical Physics, 2015, 143 (18), pp.184116. ⟨10.1063/1.4935065⟩. ⟨hal-01308776⟩