Classical density functional theory of solvation in molecular solvents: Angular grid implementation

The solvation properties of a solute in a molecular solvent can be obtained by minimization of a position and orientation-dependent free-energy density functional, with the unknown excess term approximated by the angular-dependent direct correlation function of the pure solvent. We show how this function can be extracted from MD simulations of the pure solvent by computing the pair distribution function and solving subsequently the Molecular Ornstein–Zernike equation using angular grids. The corresponding functional can be minimized in the presence of an arbitrary solute on a three-dimensional cubic grid for positions and Gauss–Legendre angular grid for orientations to provide the solvation structure and free-energy. Applications are presented for solvation in acetonitrile.