A multispectrum analysis of the ν2 band of H 12C 14N: Part II. Theoretical calculations of self-broadening, self-induced shifts, and their temperature dependences

Abstract

A semiclassical theory based upon the Robert–Bonamy formalism has been developed to explain the experimental measurements of self-broadening, self-induced pressure shift coefficients in the ν 1, ν 2, 2 ν 2 bands of H 12C 14N and the 2 ν 1 band of H 13C 14N, as well as the temperature dependences of these parameters with special emphasis on the ν 2 band. Our calculations include only electrostatic interactions and neglect the vibrational dependence of the isotropic part of the intermolecular potential, which probably has a weak contribution to the HCN self-shifts for the bands investigated in this study. The agreement between theory and measurements is good in the cases of self-broadening coefficients and their variation with temperature, as well as the self-shift coefficients determined at room temperature. However, the observed temperature dependence of self-shift coefficients in the ν 2 band is different from that derived theoretically.