Average local electrostatic potential and the core‐valency separation in atoms

The average local electrostatic potential function, V(r)/ ρ(r), is calculated for 87 atoms, Li‐Ac, in the ground state using the nonrelativistic average‐over‐configuration numerical Hartree‐Fock density. It is found empirically that in a given atom the shell boundaries are expressed as the successively increasing maxima in V(r)/ ρ(r) and the outermost maximum presents good approximate estimates of the core‐valence separation in atoms. The likeness in behavior of V(r)/ ρ(r) at each shell boundary with the maximum hardness principle is discussed. The single‐exponent‐fit parameters for the electron density in the valency region are provided for all atoms.