′�?, by using a frequency of 295 cm−1, is attributed on the stretching vibration of Ga–Se bonds. The two-phonon absorption in the 295 cm−1 phonon corresponds to the crystal IR absorption edge, rather than the residual absorption peak. Density functional idea computations clearly show the residual absorption in the BGSe https://messiahcavnf.suomiblog.com/baga4se7-crystal-an-overview-48291575