Abstract
We investigate the properties of norm-conserving pseudopotentials (effective core potentials) generated by inversion of the Hartree–Fock equations. In particular, we investigate the asymptotic behavior as r→∞ and find that such pseudopotentials are nonlocal over all space, apart from a few special cases such as H and He. Such extreme nonlocality leads to a lack of transferability and, within periodic boundary conditions, an undefined total energy. The extreme nonlocality must therefore be removed, and we argue that the best way to accomplish this is a minor relaxation of the norm-conservation condition. This is implemented, and pseudopotentials for the atoms H–Ar are constructed and tested.