Correlation Potentials and Compact Orbital Expansions (pp. 15-26)
Authors: Jerry L. Whitten
Abstract: The concept of a correlation environment that leads to a two-electron correlation potential is discussed. The potential captures dynamical correlation effects without explicitly including a large number of higher order spherical harmonic functions in the basis set. It can be used in both self-consistent-field and configuration interaction calculations and its formulation makes use of compact basis orbital expansions. An optimization strategy is described to determine basis orbital expansions for atoms or small molecular units that meet specified design criteria such as compactness and orthogonality.