Potential energy surface of 4-hexyl-4′-cyanobiphenyl (6CB) on graphite surface: a DFT study with van der Waals corrections

Abstract

The potential energy surface (PES) between a 4-hexyl-4′-cyanobiphenyl (6CB) molecule and a graphite surface was calculated by the first-principles method based on the density functional theory with empirical van der Waals (vdW) corrections. The parameters of the empirical vdW corrections were derived by fitting the PESs for the benzene–methane, benzene dimer and benzene–benzonitrile molecules to high-level ab initio calculations. The obtained potential energy minimum between 6CB and graphite surface for a configuration was ca. − 27.8 kcal/mol. Based on this PES, we determined the force-field parameters between 6CB and graphite surface to be used in classical molecular simulations in the future work.