Ab initioinvestigation of the vibronic structure of the C2H spectrum

Abstract
A purely ab initio study of the vibronic structure of the X 2Σ+, A 2Π system of C2H is presented. An approach is developed for a simultaneous treatment of three electronic states coupled via the bending and C-C stretching vibrations. On the basis of the results of the present calculations, it is possible to reliably interpret previous experimental findings.