Variational R-matrix calculations for singly and doubly excited singlet gerade channels in H{sub 2}

Journal Article · Thu Jul 01 04:00:00 EDT 2004 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.70.012713· OSTI ID:20645763

Bezzaouia, S; Telmini, M ^[1]; Jungen, Ch ^[2]

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1. LSAMA Department of Physics, Faculty of Sciences of Tunis, University of Tunis El Manar, 2092 Tunis (Tunisia)
2. Laboratoire Aime Cotton du CNRS, Universite de Paris-Sud, 91405 Orsay (France)

Variational ab initio R-matrix theory is combined with generalized multichannel quantum defect theory, implemented in spheroidal coordinates, to calculate clamped-nuclei {sup 1}{sigma}{sub g}{sup +}, {sup 1} product {sub g}, and {sup 1}{delta}{sub g}{sup +} electron-ion scattering phase shift matrices for H{sub 2}. The calculations cover the bound state region below H{sub 2}{sup +} 1{sigma}{sub g}, the resonance region between H{sub 2}{sup +} 1{sigma}{sub g} and H{sub 2}{sup +} 1{sigma}{sub u}, and they extend beyond the H{sub 2}{sup +} 1{sigma}{sub u} threshold. They span the range of internuclear distances 1{<=}R{<=}5 a.u. The use of spheroidal instead of spherical coordinates allows a restricted partial wave expansion to be used, thus yielding a compact set of interaction parameters pertaining to the electron-ion scattering dynamics in H{sub 2}. The accuracy of our fixed-nuclei quantum defects is generally of the order of about 0.02. At the same time the quantum defect matrices obtained here exhibit a smooth behavior across the ionization thresholds and their elements also vary rather smoothly with internuclear distance. These results represent a step toward the goal of constructing a unfied theoretical description of ionization and dissociation fragmentation dynamics of H{sub 2}.

• OSTI ID: 20645763
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 70; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
BOND LENGTHS
BOUND STATE
CURVILINEAR COORDINATES
DEFECTS
DISSOCIATION
DISTANCE
ELECTRONS
EXCITED STATES
HYDROGEN
HYDROGEN IONS 2 PLUS
IONIZATION
PARTIAL WAVES
PHASE SHIFT
R MATRIX
RECOMBINATION
RESONANCE
SCATTERING
VARIATIONAL METHODS