While the quasi-harmonic approximation does include some temperature dependence, by allowing for thermal expansion, it does not give a complete description of the non-zero temperature phonon behaviour. In particular, phonon modes within the QHA are assumed to be noninteracting and have infinite phonon lifetimes. To go beyond the QHA and to consider a fully anharmonic phonon model, we have performed a series of "ab initio" molecular dynamics simulations (AIMD). We have then used the post-processing software DYNAPHOPY to extract the phonon frequencies and phnon lifetimes as a function of temperature. DYNAPHOPY uses atom velocities, v jl (t), which can be directly derived from AIMD trajectories, to compute the velocity auto-correlation function