Vibrational features of water’s amorph at high pressures

The specific heat Cₚ and thermal conductivity κ of water's high density amorph have been measured as a function of pressure up to 1.20.3em0exGPa. Cₚ decreases on an increase in the pressure and κ increases, both approaching a plateau value asymptotically. The decrease in Cₚ on an increase in pressure is shown to be due to increase in the phonon frequency. The Debye temperature calculated from the available sound velocity data increases asymptotically with an increase in pressure and increases approximately linearly with an increase in the density of the amorph. The Gr\"uneisen parameter of the high density amorph is 1.3. While the Debye theory explains the variation of Cₚ with pressure, it does not seem to do so for the variation of κ with pressure.