′�?, by using a frequency of 295 cm−one, is attributed for the stretching vibration of Ga–Se bonds. The two-phonon absorption from the 295 cm−1 phonon corresponds into the crystal IR absorption edge, instead of the residual absorption peak. Density functional theory computations clearly show the residual absorption of the BGSe https://rafaelpkfhe.blog5.net/75689422/5-simple-techniques-for-baga4se7-crystal