Hulthèn Transform Functions of Two-Electron Atomic Systems

Hulthèn-type functions are considered as special integral transform functions (Hulthèn transforms) and are used to approximate the ground-state closed-shell and open-shell and also the 21P excited-state wavefunctions of some two-electron atomic systems. The ground-state energies obtained are lower than those obtained with Slater functions. In contrast, for the 21P excited state, Slater functions give energies as good as Hulthèn transform functions. The (radial) Hulthèn transform of the 2p orbital gives a better energy for the 21P state than the 1p function suggested by Parr et al.