Experimental and theoretical study of valence electronic structure of tetrabromomethane by (e,2e) electron momentum spectroscopy

Electron Momentum Spectroscopy Study on the Valence Electronic Structure of Dimethyl Sulfide Considering Vibrational Effects

“…Distinct discrepancies between the experiments and calculations were observed, especially for the 5b 2 orbital, which is mainly the C–S σ bonding orbital. Numerous factors may lead to the discrepancies, for example the deviation from plane wave impulse approximation (PWIA) (distorted wave effect), − relativistic effect, − and vibrational effect. − …”

“…Therefore, the equilibrium geometry of the molecule is commonly invoked to calculate theoretical momentum profiles (TMPs) when interpreting EMS results. However, recent investigations − have shown that for polyatomic molecules, the nuclear vibrational motions have noticeable influence on EMPs. To fully estimate vibrational effects on EMPs theoretically, Watanabe et al proposed a harmonic analytical quantum mechanical (HAQM) approach, , in which all the vibrational modes were taken into account and the contributions of each mode can be estimated individually.…”

“…It was demonstrated that not only the low-frequency vibrational modes − , but also the high-frequency ones ,, play important roles in interpreting the experimental EMPs. The influence of nuclear dynamics on EMPs can alternatively be analyzed using molecular dynamics simulations. − , In order to have a more detailed exploration on the nuclear dynamics effect, Morini et al investigated EMPs for a larger and structurally more flexible molecular target dimethyl ether ((CH 3 ) 2 O) . The equilibrium geometry of (CH 3 ) 2 O has C 2 v symmetry, where there is a mirror symmetry plane dividing the C–O–C angle.…”

“…The influence of nuclear dynamics on EMPs can alternatively be analyzed using molecular dynamics simulations. [51][52][53]60 In order to have a more detailed exploration on the nuclear dynamics effect, 25 at an impact energy of 1200 eV plus binding energy. Distinct discrepancies between the measured momentum profiles and calculated ones at the equilibrium molecular geometry were observed, especially for the 5b 2 orbital.…”