′�?, with a frequency of 295 cm−1, is attributed to your stretching vibration of Ga–Se bonds. The 2-phonon absorption on the 295 cm−1 phonon corresponds towards the crystal IR absorption edge, as an alternative to the residual absorption peak. Density useful theory computations show the residual absorption of the BGSe https://baga4se7-crystal63062.bloggosite.com/39224378/baga4se7-crystal-an-overview