Ab initio investigation of the Renner-Teller effect in the A³Π<inf>u</inf> electronic state of NCN

Abstract

Large-scale CI calculations are carried out to obtain accurate bending potential energy curves for the 13 A1 and 23 B1 components of the A3Πu electronic state of NCN and the electric transition moment functions for the A3Πu-X3Σg− spectral system of this molecule. These data are combined to compute the vibronic structure in the A3Πu state and the intensity distribution within the A3Πu-X3Σg− band system. The calculations reproduce reliably the results of recent measurements of the 000-000 and 010-010 transitions in the A3Πu-X3Σg− system by laser excitation spectroscopy [S. A. Beaton, Y. Ito, and J. M. Brown, J. Mol. Spectrosc. 178, 99-107 (1996); S. A. Beaton and J. M. Brown, J. Mol. Spectrosc. 183, 347-359 (1997)] and predict positions and intensities for yet unobserved bands of the same system. © 2001 Academic Press.