Harris functional densities: from solid to atom

Adaptive and transferable electron densities applicable as input in Harris density functionals and first-principles inter-atomic potentials are constructed from calculations for the atom in question embedded in a homogeneous electron gas. The density profile of each atom depends explicitly on the average density in which the atom is located, which forms the basis for the adaptivity. Harris functional results for Al and Ni atoms in numerous configurations are compared to the corresponding self-consistent results. The new density construction is shown to give systematically better results than superimposed fixed atom-like densities.