H2O halfwidths and lineshifts in 3v1+v3 band induced by Ar pressure

ABSTRACT Halfwidths and lineshifts of water vapour by Ar pressure were calculated in the framework of semiclassical broadening theory 1,2Anisotropic and isotropic parts of polarization interactions are taken into account, when relaxation parameters are calculated. H20mean polarizability in 301 vibrational state was determined earlier using the measured linesfifts . H20 polarizability z-component in301 vibrational state was determined using the measured lineshifts in this work at the first time. The calculated relaxation parameterswere in a good agreement with the measured one Halfwidths and lineshifts temperature dependence is calculated within the interval100-800 K. Keywords: halfwidth, lineshift, mean polarizability, polarizability z-component, highly excited vibrational states, rotational dependence ofrelaxation parameters, temperature dependence ofrelaxation parameters 1. INTRODUCTION It is known , that absorbing molecule vibrational excitation changes strongly the multipole moments and polarizabilitymean values, which cause intermolecular interactions of colliding molecules. Line centre shifts keep a wide informationabout intermolecular potential and intramolecular properties of absorbing molecules. It was shown in ,