Static calculations of either hydrogen bonding motif show little correlation with experiment either in terms of peak position or relative peak intensities. Both dynamic calculations show much better overall correlation with experiment with both calculations and experiment showing a broad feature below 80 cm -1 comprising several modes, and a second broad feature centred around 100 cm -1 . In the disordered system the modes centred around 100 cm -1 splits into two clear peaks with a width and relative intensity that much more closely resembles experiment.