Dispersion forces and long-range electronic transition dipole moments of alkali-metal dimer excited states

Journal Article · Sat Jul 01 04:00:00 EDT 1995 · Physical Review A

DOI:https://doi.org/10.1103/PhysRevA.52.311· OSTI ID:76493

Marinescu, M; Dalgarno, A ^[1]

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1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States)

A formalism of degenerate perturbation theory is presented, in which the initial basis set of functions is fully adapted to the perturbation. This full adaptation is obtained by imposing a simple condition which leads to an iteration procedure free of singularities. The formalism includes as a special case nondegenerate perturbation theory. By using it we calculate the dispersion coefficients of alkali-metal dimers for molecular states which dissociate into one atom in the ground state and the other in one of the first two {ital S}, {ital P}, or {ital D} excited states. The dispersion forces are extracted from the first- and second-order energy corrections. Model potentials are used in order to describe the motion of the valence electron in the field of the alkali-metal positive-ion core. Using the first-order wave-function correction, we investigate the leading terms of the long-range expansion of the electronic transition dipole moments. An extension of the Dalgarno-Lewis method is developed in order to handle the radial matrix elements which involves a reduced Green`s function for real and complex energies. The results are compared with previous computations.

• OSTI ID: 76493
• Journal Information: Physical Review A, Journal Name: Physical Review A Journal Issue: 1 Vol. 52; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ALKALI METAL COMPLEXES
DIMERS
DIPOLE MOMENTS
DISSOCIATION
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
GREEN FUNCTION
PERTURBATION THEORY