Indexed on: 24 Dec '11Published on: 24 Dec '11Published in: The Journal of chemical physics
Addition of a dispersion-energy correction to density-functional theory significantly improves potential-energy curves for dispersion-bound complexes. The exchange-hole dipole moment (XDM) model allows non-empirical calculation of atomic and molecular dispersion coefficients using only occupied orbitals and polarizabilities. In this work, the XDM model is applied to examine the dependence of dispersion coefficients on changes in atomic environment, such as charge, oxidation state, and hybridization. The variations in dispersion coefficients, and resulting energy contributions, are assessed for selected chemical examples.