SPATIAL GENERALIZATIONS OF KATOS CUSP CONDITION FOR 2-ELECTRON ATOMS WITH CORRELATIONS

In this work we study two functions, f(r) and g(r), related to spatial generalizations of Kato's cusp condition for the one-electron density . In particular, we evaluate these functions using accurate correlated densities for low-lying S-states of two-electron atoms. These functio ns reveal the effects of the electron repulsion and are very sensitive to Coulomb correlations, showing interesting features in the comparis on between singlet and triplet states. In addition to this, some relat ionships between rho(0) and radial expectation values, previously foun d from the HF properties of these functions, are extended to more accu rate descriptions of these states.