Comment on “Cusp relations for local strongly decaying properties in electronic systems”

In a recent paper [Phys. Rev. A 52, 2645 (1995)], Liu et al. presented an approach for obtaining physical properties at the nuclear cusps. They compared it with the Hiller-Sucher-Feinberg (HSF) identity [Phys. Rev. A 18, 2399 (1978)] and found theirs to be superior. It is shown here that this conclusion is based on the comparison on equal footing of different types of identities, namely physical in the case of HSF and mathematical in the case of Liu et al.