′�?, with a frequency of 295 cm−one, is attributed into the stretching vibration of Ga–Se bonds. The 2-phonon absorption on the 295 cm−1 phonon corresponds into the crystal IR absorption edge, as opposed to the residual absorption peak. Density functional idea computations clearly show the residual absorption in the BGSe https://dantebjlll.idblogmaker.com/31985291/everything-about-baga4se7-crystal