Ab initio simulation of the fundamental vibrational frequencies of selected pyrite-type pnictides

DFT calculations on pyrite-type SiP2, PtN2, PtP2 and PtAs2 have been performed using the Crystal06 code for the simulation of fundamental vibrational frequencies in periodic systems. The obtained spectra of SiP2, PtP2 and PtAs2 are in very good agreement with available Raman and IR studies. The vibrational spectra of the novel PtN2 is calculated including Raman and IR data. The results are discussed with respect to the dumbbell structural units and related compounds.