A configuration interaction (CI) procedure for the evaluation of twohyphen;photon electronic transition probabilities. Program implementation with application to theA1grarr;B2utransition of benzene

摘要

A CI program is described for the evaluation of twohyphen;photon electronic transitions, based on time dependent second order perturbation theory. The expression of the transition amplitudes is obtained by directly solving first order perturbation equations over the CI components, avoiding the second order expression with summation over the full set of the intermediate CI eigenstates. The procedure has been implemented as part of a general CI program forabinitiocomputations of these properties. To test the program, the relative intensities of the lsquo;lsquo;hotrsquo;rsquo; vibronic components of theA1grarr;B2utransition of the benzene molecule have been evaluated on a minicomputer and compared to the experiment.