Hy-CI Study of the 2 doublet S Ground State of Neutral Lithium and the First Five excited doublet S States

Published

November 19, 2009

Author(s)

James S. Sims, Stanley A. Hagstrom

Abstract

High precision Hylleraas-Configuration Interaction (Hy-CI) method variational calculations are reported for the 2 doublet S ground state of neutral lithium. The nonrelativistic energy is calculated to be -7.4780 6032 3451 9 hartree, demonstrating that the Hy-CI technique is capable of sub-nanohartree accuracy for three electron systems. A Hylleraas (Hy) expansion without linked products of odd powers of $r_{ij}$ gives -7.4780 6032 3452 hartree, showing the relative unimportance of such terms for lithium at the nanohartree level of accuracy. Hy-CI calculations are also reported for the 3 doublet S, 4 doublet S, 5 doublet , 6 doublet and 7 doublet S lithium excited states.

Citation

Physical Review A (Atomic, Molecular and Optical Physics)

Volume

80

Pub Type

Journals

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Keywords

Hylleraas-Configuration Interaction, Hy-CI variational calculation, CI-Hy variational calculation, high precision variational calculation, lithium ground state calculation, lithium doublet S excited states

Citation

Sims, J. and Hagstrom, S. (2009), Hy-CI Study of the 2 doublet S Ground State of Neutral Lithium and the First Five excited doublet S States, Physical Review A (Atomic, Molecular and Optical Physics), [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=903756 (Accessed October 23, 2025)