Physical Review A - Atomic, Molecular, and Optical Physics
Nonrelativistic energy and other properties of He, H- and Ps- were discussed using a triple basis set in Hylleraas coordinates. The stability and efficiency of the computational method was compared with the quasirandom method. Results showed that the triple basis set in Hylleraas coordinates is capable of exceeding the accuracy of calculations for three-body system based on quasirandom Monte Carlo methods.
Drake, Gordon W. F.; Cassar, M. M.; and Nistor, R. A.. (2002). Ground-state energies for helium, H-, and Ps-. Physical Review A - Atomic, Molecular, and Optical Physics, 65 (5 B), 545011-545014.