The strong hydrogen bonds in high-density amorphous ice at high pressures

We have investigated the change of in situ Raman spectra of high-density amorphous ice (HDA) as functions of pressure and temperature. Here we show the spectral evidence for the formation of strong hydrogen bonds in HDA at high pressures and the close similarity in spectral features of relaxed HDA to that of supercooled water at high pressures and low temperatures. It can be also suggested that pressure-induced amorphization is a collapsed transition and HDA is not a glassy state of liquid water.