2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/106987Ab initio approaches are introduced for calculations of inelastic losses and vibrational damping in core level x-ray and electron spectroscopies. From the dielectric response function we obtain system-dependent self-energies, inelastic mean free paths, and losses due to multiple-electron excitations, while from the dynamical matrix we obtain phonon spectra and Debye-Waller factors. These developments yield various spectra and optical constants from the UV to x-ray energies in aperiodic materials, and significantly improve both the near edge and extended fine structure.10 pages, 4 figures, 1 TableMaterials ScienceOther Condensed Mattertext