Quantities T sub s ( n ) and T sub c ( n ) in density-functional theory

Levy's constrained-search procedure (Proc. Natl. Acad. Sci. U.S, North 76, 6062 (1979)) is employed to show how to determine Kohn-Sham and Hartree-Fock-Kohn-Sham orbitals and kinetic energies {ital T}{sub {ital s}} and {ital T}{sub {ital c}}, for the two-electron, four-electron, and the general case starting from the electron density. Numerical results are presented for the species H{sup {minus}} through {ital F}{sup 7+} and the atom Be. The Pauli potential is also determined for Be. The small differences among Kohn-Sham, Hartree-Fock, and Hartree-Fock-Kohn-Sham orbitals suggest that determination of Kohn-Sham orbitals from the density in this way is an attractive procedure for getting an orbital description from an electron density.