Interaction of hydrogen atoms with polyatomic molecules studied by means of scattering experiments and hybrid Hartree-Fock plus damped dispersion calculations

Total differential collision cross sections for the scattering of H atoms from ethane (C2H6), propane (C2H8), acetylene (C2H2), and O2 have been measured and information on the spherical and nonspherical parts of the interaction potential extracted by means of scattering calculations which make use of the infinite-order sudden (IOS) approximation. The interactions of three other systems, H + Ar, H + CH4, and H + CO, previously measured in our laboratory have been calculated by means of hybrid Hartree-Fock plus damped dispersion (HFD) energy calculation and found to be in good agreement with the experimental potentials. A model is then constructed to derive the main features of the interaction of H atoms with the higher hydrocarbons from the knowledge of the H + CH4 interaction. The predictions of this model are found to be in excellent agreement with the experimental parameters for both the spherical and nonspherical parts of the potentials. 4 figures, 9 tables