Difference in the Potential Energy Surfaces from the Fragment MO Method and Conventional Ab Initio SCF-MO Method. A Case of a Surface for Ring Rotation of (−)-Epicatechin Gallate Using the STO-3G Basis Set

Abstract

Abstract Difference in the potential energy surfaces (ΔE) obtained from the fragment MO (FMO) method and conventional ab initio Hartree–Fock SCF-MO (HFMO) method was investigated using the best fragmentation pattern of (−)-epicatechin gallate. In the lower energy region (<23.06 kcal mol−1 from the minimum), the average ΔE at each grid point was 1.1 kcal mol−1. The FMO method is applicable to quantum MD calculation of large molecular system at around the standard temperature.