Skip to main content

NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

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

Published

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

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 9, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created November 19, 2009, Updated February 19, 2017
Was this page helpful?