Hylleraas-Configuration Interaction study of the 1S ground state of the negative Li ion

J Phys B At Mol Opt Phys. 2017 Dec 28;50(24):245003. doi: 10.1088/1361-6455/aa961e. Epub 2017 Nov 20.

Abstract

In a previous work Sims and Hagstrom [J. Chem. Phys. 140, 224312 (2014)] reported Hylleraas-Configuration Interaction (Hy-CI) method variational calculations for the neutral atom and positive ion 1S ground states of the beryllium isoelectronic sequence. The Li- ion, nominally the first member of this series, has a decidedly different electronic structure. This paper reports the results of a large, comparable calculation for the Li- ground state to explore how well the Hy-CI method can represent the more diffuse L shell of Li- which is representative of the Be(2sns) excited states as well. The best non-relativistic energy obtained was -7.500 776 596 hartree, indicating that 10 - 20 nh accuracy is attainable in Hy-CI and that convergence of the r12r34 double cusp is fast and that this correlation type can be accurately represented within the Hy-CI model.

Publication types

  • Research Support, U.S. Gov't, P.H.S.