Theoretical Evaluation of the Fractional Hyperfine Pressure Shift of Paramagnetic Atoms in a Noble Gas

Abstract

The fractional hyperfine pressure shift (known as HPS in the literature) of paramagnetic atoms in an atmosphere of noble-gas atoms has been found to be computable quite adequately from recently evaluated extended-basis-set self-consistent-field molecular-orbital wave functions. The actual computation was carried out for lithium and sodium atoms in a helium buffer gas. Computed values of 78.87 × ${10}^{-9\mathrm{}}$/mm Hg versus the experimental value of 77.7 × ${10}^{-9\mathrm{}}$/mm Hg for LiHe and 78.11 versus 73.0 × ${10}^{-9\mathrm{}}$/mm Hg for NaHe were obtained.