Author(s)

Diana Kaeen¹, Mahmoud Korek^1*, Saleh Nabhan Abdulal², Ramadan Awad²

¹Physics Department, Faculty of Science, Beirut Arab University, Beirut, Lebanon.
²Physics Department, Lebanese International University, Beirut, Lebanon.

The potential energy curves of the lowest 20 electronic states in the representation ^2s+1Λ^(±) of the molecule PbO have been investigated via ab initio CASSCF and MRCI (single and double excitations with Davidson correction) calculations. The spectroscopic constants such as vibrational harmonic frequency ω_e, the internuclear distance at equilibrium R_e, the rotational constant B_e, and the electronic transition energy T_e with respect to the ground state have been calculated along with the permanent dipole moment for the different bound investigated electronic states. By using the canonical functions approach, the eigenvalues E_v, the rotational constant B_v and the abscissas of the turning points R_min and R_max have been calculated. The comparison of these values with those available in the literature shows a very good agreement.

Ab Initio Calculation, PbO Molecule, Potential Energy Curves, Spectroscopic Constants, Dipole Moment, Rovibrational Calculation

Kaeen, D. , Korek, M. , Abdulal, S. and Awad, R. (2015) Theoretical Calculation of the Low-Lying Electronic States of the Molecule PbO. Journal of Modern Physics, 6, 1171-1183. doi: 10.4236/jmp.2015.68121.