′�?, with a frequency of 295 cm−1, is attributed into the stretching vibration of Ga–Se bonds. The 2-phonon absorption from the 295 cm−one phonon corresponds to the crystal IR absorption edge, in lieu of the residual absorption peak. Density functional idea computations display the residual absorption in the BGSe crystal https://baga4se7crystal73950.bloggip.com/32701011/the-smart-trick-of-baga4se7-crystal-that-nobody-is-discussing