Comment on “Density functional theory is straying from the path toward the exact functional”

Abstract

Medvedev et al . (Reports, 6 January 2017, p. 49) argue that recent density functionals stray from the path toward exactness. This conclusion rests on very compact 1s 2 and 1s 2 2s 2 systems favored by the Hartree-Fock picture. Comparison to actual energies for the same systems indicates that the “straying” is not chemically relevant and is at best specific to the studied dense systems.