Ionic thermal effects on photo-electron emission within time-dependent density-functional theory*
1 Laboratoire de Physique Théorique,
Université Paul Sabatier, CNRS, Toulouse, France
2 Institut für Theoretische Physik, Universität Erlangen, Staudtstraße 7, 91058 Erlangen, Germany
Received in final form: 18 December 2015
Published online: 2 February 2016
We study the impact of thermal fluctuations of cluster/molecule shape on photo-electron spectra (PES) and photo-electron angular distributions (PAD) using a detailed time-dependent simulation of the emission dynamics and thermal ionic motion. Basis of the description is time-dependent density-functional theory (TDDFT) coupled to molecular dynamics for ionic motion. Test cases are small Na clusters and the C3 molecule. For Na clusters, we find that PES signals are rather robust for one-photon processes while large smearing of the pattern are observed at lower frequencies in multi-photon processes. This effect can be related to the typical spectral response of the metal clusters. PAD are generally much more robust than PES. The C3 molecule produces a greater variety of thermal response. This happens because this molecule has eigenmodes with much different softness.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2016