H2-broadening, shifting and mixing coefficients of the doublets in the 2 and 4 bands of PH3 at room temperature

The broadening, shifting and mixing coefficients of the doublet spectral lines in the (2) and (4) bands of PH3 perturbed by H-2 have been determined at room temperature. Indeed, the collisional spectroscopic parameters: intensities, line widths, line shifts and line mixing parameters, are all grouped together in the collisional relaxation matrix. To analyse the collisional process and physical effects on spectra of phosphine (PH3), we have used the measurements carried out using a tunable diode-laser spectrometer in the (2) and (4) bands of PH3 perturbed by hydrogen (H-2) at room temperature. The recorded spectra are fitted by the Voigt profile and the speed-dependent uncorrelated hard collision model of Rautian and Sobelman. These profiles are developed in the studies of isolated lines and are modified to account for the line mixing effects in the overlapping lines. The line widths, line shifts and line mixing parameters are given for six A(1) and A(2) doublet lines with quantum numbers K = 3n,(n = 1,2, ...) and overlapped by collisional broadening at pressures of less than 50 mbar. [GRAPHICS] .