Dynamic polarizabilities of rare-earth-metal atoms and dispersion coefficients for their interaction with helium atoms

Journal Article · Thu Mar 15 04:00:00 EDT 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.75.032723· OSTI ID:20982343

Chu, Xi; Dalgarno, Alexander; Groenenboom, Gerrit C ^[1]

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1. Department of Chemistry, University of Montana, Missoula, Montana 59812 (United States)

The dynamic scalar and tensor polarizabilities of the rare-earth-metal atoms are calculated with time-dependent density functional theory. The frequency-dependent polarizabilities at imaginary frequencies are used to determine the isotropic and orientation-dependent van der Waals coefficients for the interactions of the rare-earth-metal atoms with helium atoms. The static polarizabilities are compared with other theoretical values and with experimental results. The agreement is satisfactory in most cases but there are some exceptions where the discrepancy between theory and experiment is significant. The derived isotropic van der Waals coefficients range between 37 and 50 E{sub H}a{sub 0}{sup 6} and the orientation-dependent coefficients between 2 and -1 E{sub H}a{sub 0}{sup 6}. Thus the ratio of elastic to inelastic scattering cross sections is expected to be substantial and any one of the rare-earth-metal atoms is an excellent candidate for trapping and cooling in a He gas.

• OSTI ID: 20982343
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 3 Vol. 75; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOM-ATOM COLLISIONS
ATOMS
COOLING
CROSS SECTIONS
DENSITY FUNCTIONAL METHOD
FREQUENCY DEPENDENCE
HELIUM
INELASTIC SCATTERING
INTERACTIONS
POLARIZABILITY
RARE EARTHS
TIME DEPENDENCE
TRAPPING
VAN DER WAALS FORCES