Место издания:Publishing House of IAO SB RAS Tomsk
Первая страница:75
Аннотация:The electric dipole transition moments (EDTM) of rubidium and cesium dimers have been calculated between all electronic states converging to the lowest three dissociation limits. The adiabatic energies and relevant quasi-relativistic matrix elements were evaluated for a wide range of internuclear distance in the basis of the spin-averaged wave functions corresponding to pure Hund's coupling case (a) by using of both shape and energy consistent small (9-electrons) effective core pseudopotentials (ECP) [1]. The dynamic correlation has been accounted for a large scale multi-reference configuration interaction method which was applied for only two valence electrons keeping the rest frozen, i.e. in a full valence (2-electrons) CI scheme. The angular-independent core-polarization potential (CPP) was employed together with the above small core ECPs to take into account for the residual core-valence effect. All calculations were performed by means of the MOLPRO v.2010.1 program package [2].
The asymptotic behavior of the transition moments at large internuclear distances is analyzed in the framework of long-range and single channel quantum-defect theories. The assessment of accuracy of the present results is discussed by a comparison with preceding ab initio calculations [3] and their atomic counterparts. The semi-empirically scaled EDTM functions were finally applied to predict lifetimes and emission branching ratios for the low-lying states of rubidium and cesium dimmers due to little-known approximate sum rules [4]. These radiative properties could be useful, for example, for the decay rate estimates of the states involved in multi-state optical cycles to produce ultra cold ground state molecules by photoassociation and stimulated Raman processes.
This research was supported by RFBR grant No. 13-03-00446a.
References
1. I. S. Lim, et al, J. Chem. Phys. 122, 104103-12. (2005)
2. H. -J. Werner, et al. MOLPRO, version 2010.1, a package of ab initio program.
3. A-R Allouche and M. Aubert-Frecon, J. Chem. Phys. 136, 114302-15 (2012)
4. A. V. Stolyarov and V. I. Pupyshev, Phys. Rev. A 49, 1693-7 (1994)