ROTATIONALLY AND VIBRATIONALLY INELASTIC-SCATTERING OF GLYOXAL BY HELIUM AT AN ENERGY OF 96 MEV

Results of quantum calculations on rotationally and vibrationally inelastic scattering from four vibrational levels of 1Au (S1) trans-glyoxal (in collisions with helium, at a collision energy of 96 meV) are reported. The results can serve as predictions to be borne out by experiments that have already been carried out, but have not been analyzed yet. The calculations predict that rotationally inelastic scattering should be similar for scattering from the 00, 51 and 81 levels, but different for scattering from the 72 level. A comparison of the glyoxal+He results with results for scattering of vibrationless deuterated glyoxal also presented here shows that, at a collision energy of 96 meV, rotational excitation of glyoxal by helium is governed by angular momentum transfer rather than by energy transfer. Vibrationally inelastic scattering is dominated by the lowest frequency ν7 torsional mode, but the calculations predict that transitions involving other vibrational modes should also be observable. © 1990.