Theoretical study of the excited states of the $Rb_2$ diatomic molecule

Abstract

Adiabatic potential energy curves of $Rb_2$ diatomic molecule are calculated by an initio quantum calculation, multireference configuration interaction (MRCI) using small--core (9 valence electrons) scalar relativistic effective core potential (ECP) and core polarization potential (CPP) which includes l dependency. Spectroscopic constants, $R_e$, $D_e$, $ω_e$ and $T_e$ of ground and 57 excited states are determined solving ro-vibrational Schr\"odinger equations numerically with the calculated potential energy curves. When compared with available experimental data, $R_e$``s fall in agreement within ~0.09Å, $D_e``s$ within ~$237cm^{-1}$, $ω_e``s$ within ~$2cm^{-1}$ and $T_e``s$ within ~$123cm^{-1}$ except for $2^1∏_g$ state. The spectroscopic constants of highly excited states are refined.