AB-INITIO INFRARED-ABSORPTION STUDY OF THE HYDROGEN-BOND SYMMETRIZATION IN ICE

We computed from first principles the infrared spectrum of ice at high pressure in the molecular phases VIII and VII and in the symmetric ph ase X by performing Car-Parrinello molecular dynamics simulations and evaluating the electronic polarization by means of the Berry phase for mulation. The theoretical spectra are in good agreement with the exper imental data and let us establish an unambiguous correspondence betwee n the infrared spectrum and the underlying structure of the three diff erent phases of ice. [S0031-9007(98)06844-6].