The Rovibrational Dependence of the 14N Nuclear Quadrupole Coupling Constants in the X2Σ+ and B2Σ+ States of CN from the Multireference CI Approach

Abstract

In using several augmented correlation-consistent basis sets and reference configuration spaces, the 14N quadrupole coupling constants (QCCs) of rovibrational levels of the X2Σ+ and B2Σ+ states of the CN radical are computed from internally contracted multireference configuration interaction wave functions. To examine the overall quality of the correlated wave functions used for computing the expectation values of the electric field gradient (EFG) tensor at the N nucleus, electric dipole moments are calculated and spectroscopic constants are derived from corresponding potential energy curves. The adequacy of the expectation value approach to the evaluation of the EFG and dipole moment is discussed. The calculated vibrational dependence of the 14N QCC compares reasonably with the available experimental data.