Comparison of ultrafast electron and X-ray diffraction - a computational study

We compare ultrafast electron and X-ray diffraction using quantum molecular dynamics simulations in photoexcited ethylene. The simulations of ethylene are done using the ab-initio multiconfigurational Ehrenfest (AI-MCE) approach, with electronic structure calculations at the SA3-CASSCF(2,2)/cc-ppVDZ level. The diffraction signal is calculated using the independent atom model. We find that the electron diffraction is more sensitive the dynamics of the hydrogen atoms in the molecule.