′�?, having a frequency of 295 cm−1, is attributed on the stretching vibration of Ga–Se bonds. The two-phonon absorption on the 295 cm−one phonon corresponds towards the crystal IR absorption edge, as opposed to the residual absorption peak. Density practical idea computations clearly show the residual absorption in the BGSe https://alexispfsdk.blogaritma.com/31176521/examine-this-report-on-baga4se7-crystal