Relativitic spin-orbit configuration interaction study of the electronic spectrum of PbO

Potential energy curves for the valence electronic states of PbO are calculated using Ab initio relativistic quantum mechanical configuration interaction calculations. These calculations incorporate relativistic effective core potentials into a spin-orbit coupling configuration interaction procedure. The spin-orbit configuration interaction (SOCI) wavefunctions generated are defined in intermediate angular momentum coupling, which is between pure Lambda-S coupling and pure o-o coupling. The importance of including spin-orbit coupling is shown by comparison to calculations that do not take this interaction into account. Calculations of molecular properties including spectroscopic constants, dipole moments and transition intensities are reported. This paper will focus on potential energies around re (3.6 to 4.6 bohr).