EGAS41 - Swansea University

41 st EGAS CP 139 Gdańsk 2009
The Born-Oppenheimer approximation breakdown in lithium
dimer
A. Stein 1 , G. Dobrev 2 , I. Temelkov 2 , A. Pashov 2,∗ , H. Knöckel 1 , E. Tiemann 1
1 Institute for Quantum Optics, Leibniz Univerity of Hanover, Welfengarten 1, 30164 Hanover,
Germay
2 Faculty of Physics, Sofia University “St. Kliment Ohridski”, 5 J. Bourchier blvd., 1164
Sofia, Bulgaria
∗ Corresponding author: pashov@phys.uni-sofia.bg
The lithium dimer is one of the most well studied dimers of alkali metals. New results
of the direct potential fit of the ground X 1 Σ + g and A1 Σ + u state potentials were reported
recently [1]. In this study the Born-Oppenheimer approximation breakdown was studied
by including in the fit adiabatic and nonadiabatic corrections for both electronic states
simultaneously. Here we report a new approach to this analysis by studuing the Born-
Oppenheimer approximation breakdown separately for the X 1 Σ + g and the A 1 Σ + u electronic
states. This will reduce the possible correlations between the parameters used for description
of the adiabatic and nonadiabatic corrections. New experimental data were collected
in order to support the present analysis.
References
[1] J.A. Coxon, T.C. Melville, J. Mol. Spectrosc. 235, 235 (2006)
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