Bound eigenstates for two truncated Coulomb potentials

The eigenvalue problem for two particles interacting through the attractive truncated Coulomb potential, V(r)=-Ze²/(rᵖ+βᵖ{)}1/p$, for p=1 and 2 is solved numerically. Energy eigenvalues accurate to within eight to six significant figures for the states 1s to 4f are calculated as a function of the truncation parameter {β}. It is found that the level ordering satisfies Eₙₗ>Enl' for l'. Systematics of the eigenvalues are studied and it is found that for each l value the energies are well represented by a Ritz type of formula.