(CO2)-C-13-O-16: Global treatment of vibrational-rotational spectra and first observation of the 2 nu(1)+5 nu(3) and nu(1)+2 nu(2)+5 nu(3) absorptionbands

The effective operator approach is applied to the calculation of both line positions and line intensities of the (CO2)-C-13-O-16 molecule. About 11 00 0 observed line positions of (CO2)-C-13-O-16 selected from the literature h ave been used Co derive 84 parameters of a reduced effective Hamiltonian gl obally describing all known vibrational-rotational energy levels in the gro und electronic state, The standard deviation of the fit is 0.0015 cm(-1) Th e eigenfunctions of this effective Hamiltonian have then been used in fitti ngs of parameters of an effective dipole-moment operator to more than 600 o bserved line intensities of the cold and hot bands covering the v(2) and 3v (2) regions. The standard deviations of the fits are 3.2 and 12.0% for thes e regions, respectively, The quality of the fittings and the extrapolation properties of the fitted parameters are discussed. A comparison of calculat ed hue parameters with those provided by the HITRAN database is given. fina lly, the first observations of the 2v(1) + 5v(3) and v(1) + 2v(2) + 5v(3) a bsorption bands by means of photoacoustic spectroscopy (PAS) is presented. The deviations of predicted line positions from observed ones is found to b e less than 0.1 cm(-1), and most of them lie within the experimental accura cy (0.007 cm(-1)) once the observed line positions are included in the glob al fit. (C) 2000 Academic Press.