2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/102943Particle shape and aggregation have a strong influence on the spectral profiles of infrared phonon bands of solid dust grains. In this paper, we use a discrete dipole approximation, a cluster-of-spheres code following the Gerardy-Ausloos approach and a T-matrix method for calculating IR extinction spectra of aggregates of spherical silicon carbide (SiC) particles. We compare the results obtained with the three different methods and discuss differences in the band profiles.Astrophysicstext