′�?, with a frequency of 295 cm−1, is attributed for the stretching vibration of Ga–Se bonds. The two-phonon absorption from the 295 cm−1 phonon corresponds to the crystal IR absorption edge, instead of the residual absorption peak. Density functional idea computations exhibit that the residual absorption of your BGSe crystal https://baf-crystal97395.uzblog.net/baga4se7-crystal-options-46600103