AB INITIO CALCULATIONS OF ROTATIONALLY RESOLVED INFRARED SPECTRUM OF $KNa2+$

Abstract

Ab initio variational calculations were performed on rotationally resolved infrared spectrum of $KNa_{2}^{+}$. A discrete potential energy surface was generated using the configuration interaction ansatz coupled with the frozen-core approximation, from which an analytical representation was obtained using a power series expansion employing a Dunham expansion variable. This force field was embedded in an Eckart-Watson rovibrational Hamiltoniant from which eigenenergies and eigenfunctions were calculated. An SCF dipole moment surface was generated and used to calculated absolute line intensities and square dipole matrix elements between the vibrational ground state and the lowest-lying excited states for some of the most intense transitions within the P, Q and R branches.