Improved chemical energy component analysis.

An improved SCF energy decomposition scheme is proposed in which a special treatment is introduced for those "ionic" one-center electron-electron repulsion energy contributions which arise from the use of doubly filled bonding orbitals. These terms characterize the bonding pattern rather than the state of the atoms, therefore they are attributed to the bonds and are redistributed between them in accord with the bond orders. This permits one to solve the dilemma which we had with the previous decomposition schemes, and obtain very "chemical" one- and two-center energy components, characterizing well the bonding situation in different molecules.