Density functional calculations, using Slater basis sets, with exact exchange

Abstract

We report the extension of our Slater-type orbital (STO) basis code for density functional theory (DFT) calculations to include “exact exchange,” so that Hartree–Fock and hybrid DFT calculations may be performed. Exchange integrals are evaluated through the insertion of a resolution of the identity, using the same auxiliary STO basis set which was used in our original generalized gradient approximation DFT studies. Three-center two-electron integrals are evaluated by quadrature. A scheme for introducing diatomic auxiliary STO basis sets is introduced, which enables much larger calculations to be performed. We also report an extension to the evaluation of second-order molecular properties using these functionals. Calculations for excitation energies to valence and Rydberg states are included.