′�?, having a frequency of 295 cm−1, is attributed on the stretching vibration of Ga–Se bonds. The two-phonon absorption of the 295 cm−one phonon corresponds into the crystal IR absorption edge, in lieu of the residual absorption peak. Density practical concept computations show the residual absorption from the BGSe crystal https://edgarpuvvt.blogsvila.com/32912070/everything-about-baga4se7-crystal