Direct deperturbation analysis of the A Π 2 ∼ B Σ + 2 complexof LiAr 7 , 6 isotopomers

• Published in: The Journal of chemical physics 2005-11, Vol.123 (20), p.204307-204307-9
• Main Authors: Meshkov, Vladimir V., Pazyuk, Elena A., Zaitsevskii, Andrei, Stolyarov, Andrey V., Brühl, Rüdiger, Zimmermann, Dieter
• Format: Article
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.2125747

Direct deperturbation analysis of the highly accurate experimental rovibronic term values of the A Π 2 ∼ B Σ + 2 complex of LiAr [ R. Brühl and D. Zimmermann , J. Chem. Phys. 114 , 3035 ( 2001 ) ] has been performed in the framework of inverted close-coupling approach implicitly adjusted to the unified treatment of the overall A ∼ B coupling effect without reducing the rovibrational dimensionality. The nonlinear fitting procedure was supported by the ab initio calculations on the spin-orbit and angular coupling matrix elements between the lowest X Σ + 2 , A Π 2 , and B Σ + 2 states. The analytical grid mapping based on the reduced variable representation of the radial coordinate r was used to improve the efficiency of the solution of the close-coupling radial equations near the dissociation limit. The mutual A ∼ X perturbation effect on the A Π 2 term values and spin-rotation splitting of the ground state were evaluated for both LiAr 7 , 6 isotopomers. The resulting empirical potential-energy curves for the adiabatic A Π 2 and B Σ + 2 states, along with the refined r -dependent nonadiabatic matrix elements, reproduce the total rovibronic structure of the LiAr 7 complex with the standard deviation of 0.003 cm − 1 . The mass invariance of the deperturbed electronic parameters was confirmed by the calculation of the rovibronic term values of the LiAr 6 isotopomer which coincided with their experimental counterparts within 0.004 cm − 1 .