′�?, having a frequency of 295 cm−1, is attributed for the stretching vibration of Ga–Se bonds. The 2-phonon absorption from the 295 cm−one phonon corresponds on the crystal IR absorption edge, as an alternative to the residual absorption peak. Density functional idea computations show the residual absorption from the BGSe https://dantegnrtu.blogdomago.com/31770314/a-secret-weapon-for-baga4se7-crystal