High precision variational calculations for the 1s21S state of H − and the 1s21s, 1s2s 1s and 1s2s 3s states of helium

Published in: Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms

Volume 31, Issue 1-2, pp. 7-13

DOI: 10.1016/0168-583x(88)90387-4