Physical Review A
Properties of the Goedecker-Umrigar functional for the many-electron problem and its generalization
A. Holas
Abstract
The calculational scheme for an approximate ground-state energy of a many-electron system, recently proposed by Goedecker and Umrigar (GU) [Phys. Rev. Lett. 81, 866 (1998)], is analyzed in terms of the reduced-density-matrix approach. Its underlying object, the GU density-matrix functional, is generalized, possibly leading to improved energies. Properties of the solutions of the ground-state problem obtained from the original and the generalized GU functionals are established.