The two primary peaks due to SiO4 in the FIR range is at around 450 cm-1 and another around 520 cm-1. The peak at 450 cm-1 is due to O-Si-O in-plane bending while at around 520 cm-1 is due to out-of-plane bending. How can I select which plane I should look at the planes
I did some simulations using CASTEP and the direction of oxygen atoms of the SiO4 tetrahedra are not following any particular pattern.
Thanks.