One-body energy decomposition schemes revisited: Assessment of mulliken-, grid-, and conventional energy density analyses

We propose a new energy density analysis (EDA) that evaluates atomic contributions of all energy terms, i.e., the kinetic, nuclear-attraction, Coulomb, and Hartree-Fock (HF) exchange and density functional theory (DFT) exchange-correlation energies using the Mulliken-type partitioning. Although widely used DFT exchangecorrelation functionals are nonlinear expressions in terms of density, they are decomposed into atomic contributions by focusing the linear part of the density. Numerical assessment on Mulliken-EDA, Grid-EDA, and conventional EDA has been carried out for the G2-1 set. Correlations between HF and DFT exchanges demonstrate that a consistent partitioning of all energy terms is essential for EDA. These numerical results confirm that the present Mulliken-EDA offers a more reasonable picture for the atomization process.