Investigation of electron momentum distributions for outer valence orbitals of trichlorofluoromethane by (e, 2e) electron momentum spectroscopy

The binding energy spectra and electron momentum distributions for the outer valence orbitals of trichlorofluoromethane (CFCl3) have been measured by binary (e, 2e) electron momentum spectroscopy (EMS) at an impact energy of 1200 eV + binding energy. The experimental electron momentum profiles are compared with Hartree-Fock and density functional theory (DFT) calculations with different-sized basis sets. Generally, the DFT calculations employing B3LYP functional with large basis sets of AUG-cc-pVDZ and AUG-cc-pVTZ give better description of the experimental results. But for 3e orbital, all the theoretical calculations underestimate the experiment, which is probably due to the distorted-wave effect that often occurs in π*-like molecular orbital.