2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/24445With a study of bulk GaAs and GaP, we report detailed infrared spectra and their temperature dependence from first principles. Fine features and low-temperature trends in the predicted response are confirmed by experiment. The spectra are calculated from the far-infrared through twice the frequency of the zone-center optical phonon. The treatment relies on recent developments in the theories of dielectric polarization and the phonon-phonon interaction.5 pagesMaterials Sciencetext