An interaction energy decomposition approach for the supermolecule density functional theory calculations

A method is proposed for partitioning the supermolecule interaction energy obtained from density functional theory calculations. Exploratory calculations for Ar-2 reveal serious shortcomings of several commonly used correlation functionals. There are also problems with exchange functionals resulting in unphysical behavior at long range. These findings clearly demonstrate the limitations of some commonly used functionals. (C) 2003 American Institute of Physics.