Experimental and theoretical study on electronic structure of toluene by electron momentum spectroscopy

The binding energy spectra and electron momentum distributions (EMDs) of valence orbitals in toluene molecule were measured by (e, 2e) electron momentum spectrometer. A comprehensive analysis of molecular vibrational effects on the EMDs was conducted through harmonic analytical quantum mechanical approach calculations and molecular dynamics simulations within the plane wave impulse approximation (PWIA). Furthermore, the multicenter three-distorted-wave method was employed to investigate the validity of the PWIA. A comparison between experimental measurements and theoretical predictions demonstrates that molecular vibrations have negligible effects on the EMDs, whereas the distorted-wave effects are obvious, particularly in large momentum regions.