′�?, with a frequency of 295 cm−1, is attributed for the stretching vibration of Ga–Se bonds. The 2-phonon absorption with the 295 cm−1 phonon corresponds into the crystal IR absorption edge, rather then the residual absorption peak. Density useful theory computations show which the residual absorption in the BGSe crystal https://rivermerdq.csublogs.com/39631317/helping-the-others-realize-the-advantages-of-baga4se7-crystal