(2P2)3P STATE OF H- AND THE CONVERGENCE OF THE CL SERIES

A sequence of increasingly accurate configuration interaction (CI) wave functions is used to discuss binding and the convergence of the CI series for the (2p2)3P state of H-. We get an upper bound energy Eu=-0.1253547166 a.u.(H), the lowest yet obtained, lying within an estimated 0.4 μhartree from the exact eigenvalue of Schrödinger's nonrelativistic equation. The angular energy limits define angular energy increments ΔE1 which follows the formula ΔEl≃0.18 (l+1/2)-7 a.u. for l≥4. Five or eighty per cent of binding is obtained with a three-term ψ=c 1(2p)2+c2(2p′)2+c3 (3d)2 depending on whether the 2p,2p′, and 3d orbitale are energy optimized STO's or accurate natural orbitals, respectively. © 1979 American Institute of Physics.