′�?, that has a frequency of 295 cm−one, is attributed for the stretching vibration of Ga–Se bonds. The two-phonon absorption in the 295 cm−one phonon corresponds to your crystal IR absorption edge, rather then the residual absorption peak. Density purposeful principle computations demonstrate the residual absorption of the BGSe crystal https://beautrlev.mdkblog.com/38599272/the-smart-trick-of-baga4se7-crystal-that-nobody-is-discussing