Density-functional theory with effective potential expressed as a direct mapping of the external potential;Applications to atomization energies and ionization potentials

摘要

In this paper the authors further develop and apply the direct-mapping density functional theory to calculations of the atomization energies and ionization potentials.Single-particle orbitals are determined by solving the Kohn-Sham [Phys.Rev.A.140,1133 (1965)] equations with a local effective potential expressed in terms of the external potential.A two-parametric form of the effective potential for molecules is proposed and equations for optimization of the parameters are derived using the exchange-only approximation.Orbital-dependent correlation functional is derived from the second-order perturbation theory in its Moller-Plesset-type zeroth-order approximation based on the Kohn-Sham orbitals and orbital energies.The total atomization energies and ionization potentials computed with the second-order perturbation theory were found to be in agreement with experimental values and benchmark results obtained with ab initio wave mechanics methods.