′�?, using a frequency of 295 cm−1, is attributed to the stretching vibration of Ga–Se bonds. The two-phonon absorption with the 295 cm−1 phonon corresponds to the crystal IR absorption edge, in lieu of the residual absorption peak. Density practical idea computations show the residual absorption of the BGSe crystal https://baga4s7-crystal19730.nizarblog.com/32920731/the-best-side-of-baga4se7-crystal