The difference between density functionals defined by energy criterion and density functionals defined by density criterion is studied for the exchange functional. It is shown that Slater potentials are exact exchange potentials in the sense that they yield the Hartree-Fock electron density if all operators are given by local expressions. (C) 2016 Wiley Periodicals, Inc.
Funding Agencies|Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]