Electronic states of PBr2 and PBr2+

Spectroscopic constants of nine electronic states of PBr2 and three states of PBr2+ have been determined by applying the complete active space self-consistent field (CASSCF) followed by multi-reference singles and doubles configuration interaction (MRSDCI) methods that included up to 1.2 million configurations. On the basis of our computed properties, we reassign the broad and structureless emission spectra of PBr2 to the Ã2B2(I)-X2B1 transition. The BrPBr dissociation energy and the De of the diatomic PBr have been calculated.