Electronic Structures and Potential Energy Curves for the Low‐Lying States of the CN Radical

TLDR: In this paper, 11 internuclear separations ab initio calculations have been carried out on those 59 molecular states of CN which dissociate to atomic limits up to 1DC + 2DN.

Abstract: At 11 internuclear separations ab initio calculations have been carried out on those 59 molecular states of CN which dissociate to atomic limits up to 1DC + 2DN. Four electrons are held frozen in carbon and nitrogen 1s Hartree–Fock atomic orbitals, and a full configuration interaction is carried out for the remaining nine electrons using optimized 2s and 2p Slater‐type orbitals on each atom. The 2Π calculations, which include 486 configurations, are the most complicated. Eighteen significantly bound states (De ≥ 0.84 eV) were obtained, nine of which have been observed spectroscopically. With the exception of the third 2Π state, the theoretical ordering of states agrees with experiment. Three of the states never observed experimentally (4Σ+, 4Π and 4Δ) lie below all but three of the known states of CN. Calculated spectroscopic constants are compared with experiment. The potential curves show many interesting features, including potential maxima in the 4Σ−, 2Σ−, J 2Δ, and 2Π IV bound states. By performing n...