“…Molecular configuration and geometrical calculations of DHFP were performed in the Gaussian G09w package program with the basis set of 6-311++G (2d, p) by using the B3LYP theory, which consists of Becke's three-parameter hybrid variable function and Lee-Yang-Parr's correlation function [ [24] , [25] , [26] , [27] , [28] ]. Frontier molecular orbitals and molecular electrostatic potential maps were calculated by the density functional theory B3LYP/6-311++G (2d, p) method.…”