Molecular theory of hyperfine pressure shifts in H caused by Ar and He buffers

Journal Article · Sat Nov 01 04:00:00 EST 1975 · Phys. Rev., A, v. 12, no. 5, pp. 2031-2043

DOI:https://doi.org/10.1103/PhysRevA.12.2031· OSTI ID:4122134

Ray, S

The general applicability of molecular methods for studying hyperfine pressure shifts (HPS) in a hydrogen atom caused by Ar and He noble-gas buffers has been tested thoroughly by carrying out extensive multiconfigurational self- consistent-field (MCSCF) and single-configuration self-consistent-field (SCF) calculations on ArH and HeH diatomic systems. Calculations show that for a He atom, a light noble-gas buffer, single-configuration SCF molecular wave functions are sufficiently good in reproducing the HPS result quantitatively, although qualitatively the weak, long-range polarization features are not described. However, for a heavier noble-gas buffer, such as the Ar atom, the long-range polarization effects are the strong and dominant features in the ArH binary interaction. Because of a lack of a sufficient number of proper functions for describing the long-range polarization features, the single-configuration SCF molecular wave functions do not reproduce the long-range polarization effects adequately. For ArH, therefore, MCSCF molecular wave functions, constructed with a choice of configurations which describe the dominant polarizations, are employed to reproduce the HPS result quantitatively and the long-range features qualitatively. HPS results computed by using MCSCF molecular wave functions are in excellent agreement with the experimental result. (AIP)

• Research Organization: I. Physikalisches Institut der Universitaet Heidelberg, 69 Heidelberg, West Germany
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-010264
• OSTI ID: 4122134
• Journal Information: Phys. Rev., A, v. 12, no. 5, pp. 2031-2043, Journal Name: Phys. Rev., A, v. 12, no. 5, pp. 2031-2043; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

*HYDROGEN
640302* --Physics Research--Atomic
Molecular & Chemical Physics--Atomic & Molecular Properties
ARGON-- BUFFERS-- HELIUM
N60200* --Physics (Atomic & Molecular)--Atomic & Molecular Properties
SELF-CONSISTENT FIELD HYPERFINE STRUCTURE-- POLARIZATION-- SPECTRAL SHIFT-- WAVE FUNCTIONS