THE FITTING AND PREDICTION OF VIBRATION-ROTATION SPECTRA WITH SPIN INTERACTIONS

This paper describes the solution of several problems associated with the fitting and prediction of vibration-rotation spectra with multiple spin interactions. In order to regularize arithmetic with complex operators, a modified Wang basis function is proposed which has the property of making all operators which are even powers of angular momentum pure real and all odd powers pure imaginary. Next, a generalized direction cosine operator is described, which can be calculated in a Wang basis using a spherical tensor formalism. Finally, the problem of assigning quantum numbers is addressed for the case when there are more than two interacting states. A robust algorithm for assignment and sorting of eigenvectors is presented. © 1991.