We present a study of the vibrationally resolved B 1s photoionization cross section of the BF3 molecule. A combination of high-resolution photoelectron spectroscopy measurements and of state-of-the-art calculations shows the evolution of the photon energy dependence of the cross section from a complete trapping of the photoelectron wave (low energies) to oscillat ions due to intramolecular scattering [1, 2]. These diffract ion patterns allow to access structural information of both the neutral molecule and the core -hole species generated upon photoabsoption [3].
