Divide and Conquer Interaction Energy Decomposition

Abstract

The authors present a new energy decomposition scheme, which decomposes interaction energies into electrostatic, polarization, and charge transfer contributions. The method is founded on the divide and conquer approach but is only prone to errors introduced by the basis set and the applied Hamiltonian. They illustrate the method by AM1/PM3 interaction energy decompositions on bimolecular systems and 64 water systems. Their decomposition scheme also allows for screening of charge transfer or charge transfer and polarization from intermolecular interactions. Screening of these interactions is illustrated by the charge analysis of a screened 64 water system. Their calculations indicate the importance of charge transfer, even for intermolecular separations 0.5--1.0 {angstrom} from equilibrium.