DIODE-LASER MEASUREMENTS OF AR-BROADENING COEFFICIENTS IN THE NU(2) BAND OF HCN

At-broadening coefficients have been measured for 29 lines of HCN in the P, Q, and R branches of the nu(2) band, using a tunable diode-laser spectrometer. These lines with J values ranging from 1 to 25 are located in the spectral range 640-790 cm(-1). The collisional widths obtained by fitting Rautian profiles to the measured shape of the lines are significantly larger than those derived from Voigt profiles. Semiclassical calculations of these collisional broadenings have been performed using the atom-atom intermolecular potential. The calculated results in the P, Q, and R branches are in satisfactory agreement with the experimental data. (C) 1995 Academic Press, Inc.