P. Joubert et al., QUANTUM AND SEMICLASSICAL CALCULATIONS OF H-2-HE VIBRATIONAL LINE-SHAPE PARAMETERS AT HIGH-TEMPERATURE, The Journal of chemical physics, 107(10), 1997, pp. 3845-3852
Quantum close-coupling (CC) and semiclassical (SC) calculations of bro
adening and shifting coefficients of Q(j) rovibrational lines have bee
n performed using an nb initio potential energy surface. The agreement
between the theoretical results and experimental data available up to
1000 K is very good for the broadening coefficient gamma and reasonab
le for the shift delta. The main interest is to test the validity of t
he semiclassical method versus CC calculation on a wide range of tempe
rature to allow confident application of the SC method to more complex
systems. The agreement is very satisfactory. Further the SC model per
mits a detailed analysis of the mechanisms involved in the temperature
dependence of the molecular parameters gamma and delta. (C) 1997 Amer
ican Institute of Physics.