“…The linear response approach allows one to compute LO/ TO splitting. With DFT-based models, it is possible to compute frequencies and intensities of Raman (Porezag and Pederson, 1996;Milman et al, 2009), infrared (Porezag andPederson, 1996;, inelastic neutron scattering (Ryan et al, 2011) and inelastic X-ray scattering (Winkler et al, 2008b;Bosak et al, 2009) spectra. Commonly, the IR absorption spectrum of a powder is obtained from samples embedded in a matrix such as KBr.…”