Approximate scaling properties of the density functional theory Tc for atoms

Revealed are scaling properties for T-c[rho], the kinetic-energy component of the correlation energy density functional for atoms, in terms of the total number of electrons N, the nuclear charge Z, and the total electron density at the nucleus rho(0). T-c scales well as N rho(0)/Z(8/3) for both neutral atoms up to Z=18 and the four-electron Be-like cationic species. A model is given that describes these findings, involving a density encoding the cusp information and an effective potential going like r(-4/3). (c) 2006 American Institute of Physics.