title: Properties of Augmented Kohn-Sham Potential for Energy as Simple Sum of Orbital Energies.
abstract: A recent modification to the traditional Kohn-Sham method ( Levy , M. ; Zahariev , F. Phys. Rev. Lett. 2014 , 113 , 113002 ; Levy , M. ; Zahariev , F. Mol. Phys. 2016 , 114 , 1162 - 1164 ), which gives the ground-state energy as a direct sum of the occupied orbital energies, is discussed and its properties are numerically illustrated on representative atoms and ions. It is observed that current approximate density functionals tend to give surprisingly small errors for the highest occupied orbital energies that are obtained with the augmented potential. The appropriately shifted Kohn-Sham potential is the basic object within this direct-energy Kohn-Sham method and needs to be approximated. To facilitate approximations, several constraints to the augmented Kohn-Sham potential are presented.
authors.affiliation: Department of Chemistry and Ames Laboratory, Iowa State University , Ames, Iowa 50011, United States.
authors.forename: Federico
authors.identifier: http://orcid.org/0000-0002-3223-3576
authors.initials: F
authors.lastname: Zahariev
authors.affiliation: Department of Chemistry, Duke University , Durham, North Carolina 27708, United States.|Department of Physics, North Carolina A&T State University , Greensboro, North Carolina 27411, United States.|Department of Chemistry and Quantum Theory Group, Tulane University , New Orleans, Louisiana 70118, United States.
authors.forename: Mel
authors.initials: M
authors.lastname: Levy