The electronic structure of the low lying sextet and quartet states of CrFand CrCl

The electronic structure of CrF and CrCl in X (6)Sigma(+), (6)Pi, (6)Delta, A (6)Sigma(+), (4)Sigma(+), (4)Pi, and (4)Delta states that correlate with the low lying S-6, D-6, and D-4 states of Cr+ have been studied, using lar ge atomic natural orbital (ANO) basis sets and a variety of nb initio metho ds, including multi-reference configuration interaction (MRCI) and coupled cluster with perturbative triples (RCCSD(T)). We include scalar relativisti c effects perturbatively and also explore the consequence of correlating th e 3s and 3p electrons on the transition metal. We report T-e, R-e, omega(e) , as well as dipole moments, bond energies, and charge distributions and co mpare with the available experimental data as well as previous theoretical results.