Quantum chemistry by random walk. H 2P, H+3 D3h 1A′1, H2 3Σ+u, H4 1Σ+g, Be 1S

The random-walk method of solving the Schrödinger equation for molecular wavefunctions is extended to incorporate the effects of electron spin in several one- to four-electron systems. Improved calculation procedures reduce computation requirements for high accuracy by a factor of about 10. Results are given for the systems H 2P, H+3 D3h 1A′1, H2 3Σ+u, linear equidistant H4 1Σ+g, and Be 1S.