Abstract:

We report here the first measurements of momentum profiles for the propane (C3H8)valence orbitals using high resolution (△E=0.9 eV FWHM, △p=0.1 a.u.) (e,2e) electron momentum spectrometer. The impact energy was 1200 eV with binding energy l206 to 1232 eV and symmetric non-coplanar kinematics was employed. The inner-valence spectrum is in agreement with published photoelectron data. Excited ionic states corresponding to many-body electron correlation processes were observed for propane above 25 eV. The experimental momentum profiles were compared with calculations obtained using Hartree-Fock method with the minimum basis set and a high-level basis set, and also using density functional theory (DFT) local density and nonlocal density methods with a high level basis set. The agreement between theory and experiment for the shape of orbital electron momentum distributions is generally good.

Key words: C3H8, (e,2e), Momentum spectra, Binding spectra