Electronic structure of the radicals NF and NCI. II. Potential energy curves for NCI

Abstract

Large-scale MRD CI calculations are employed to determine the potential energy curves for the three lowest X 3Σ −, a 1Δ and b 1Σ + states of NCl with π *2 configuration, for the higher states arising from σ → π *, π → σ * and π → π* excitation and for the 2Π ion. Numerous avoided crossings are found to occur between curves in the region of internuclear separations treated. A comparison with the corresponding curves for the radicals NF, O 2 and SO is undertaken and the basic similarities and distinctions are discussed. The curves in NF and NCl are quite similar, with generally lower energy gaps in the second-row radical; they can to a large extent be constructed from the homonuclear counterpart by mixing of g and u symmetry and by taking into account the different multiplicities in the dissociation products N + Cl or F and O + O or S.