Selection rules for electric multipole transition of triatomic molecule in scattering experiments

Tian Hong-Chun^{1, 2}, Xu Long-Quan^{1, 2}, Zhu Lin-Fan^{1, 2, †}

(color online) The electron energy loss spectra of CO₂ measured at an incident electron energy of 1500 eV and the scattering angles of 1.5° and 6.5°, respectively. The corresponding squared momentum transfers at 1.5° and 6.5° are 0.077 a.u. (the unit a.u. is short for atomic unit) and 1.41 a.u., respectively.