Author(s)

Sally Shawa¹, Mahmoud Korek^1*, Ghassan Younes¹, Nayla El-Kork²

¹Faculty of Science, Beirut Arab University, Beirut, Lebanon.
²Khalifa University, Sharjah, United Arab Emirates.

Complete Active Space Self Consistent Field (CASSCF) with Multireference Configuration Interaction (MRCI) and Rayleigh-Schrodinger Perturbation Theory (RSPT2-RS2) methods have been used to investigate the potential energy curves for the 12 low-lying singlet and triplet electronic states in the representation ^2s+1Λ^(+/-) of the molecule BaS with Davidson corrections. The harmonic frequency w_e, the internuclear distance R_e, the electronic energy with respect to the ground state T_e, the rotational constants B_e and the permanent dipole moment have been calculated for these electronic states. The eigenvalues E_v, the rotational constants B_v, the centrifugal distortion constant D_v and the abscissas of the turning points R_min and R_max have been investigated using the canonical functions approach. Nine new electronic states have been investigated here for the first time. The comparison between the values of the present work and those available in the literature for several electronic states shows a good agreement.

Ab Initio Calculation, Electronic Structure, Spectroscopic Constants, Potential Energy Curves, Dipole Moments, Vibration-Rotation Calculation

Shawa, S. , Korek, M. , Younes, G. and El-Kork, N. (2015) Theoretical Calculation of the Low-Lying Electronic States of the Molecule BaS. Journal of Modern Physics, 6, 610-621. doi: 10.4236/jmp.2015.65066.