EXTENSION OF ENERGY DENSITY ANALYSIS TO TREATING CHEMICAL BONDS IN MOLECULES

Abstract

We have extended the method of energy density analysis (EDA), originally proposed by Nakai (Chem Phys Lett363:73, 2002), to treat chemical bonds in molecules. The present method, termed "Bond-EDA", partitions the total energy calculated by the Hartree–Fock method not only into atomic regions, but also bond regions. Numerical applications of Bond-EDA are carried out for ethane and ethylene. The C – C and C – H dissociation processes are examined for both molecules. For ethylene, we further investigate the changes of chemical bonds by the excitation from the singlet ground state to the triplet excited state.