We predict a new pressure induced phase for silica via first principles variable-cell-shape molecular dynamics. The structure results from annealing α-quartz at pressures near a phonon instability. The mechanism which produces this new phase is similar to that proposed for structural transitions in silicate melts. The diffraction pattern of the new phase compares favorably with that of the unidentified intermediate crystal phase found in silica near the pressure induced amorphization transformation.
|Original language||English (US)|
|Number of pages||10|
|Journal||Materials Research Society Symposium - Proceedings|
|State||Published - Dec 1 1998|
|Event||Proceedings of the 1997 MRS Fall Symposium - Boston, MA, USA|
Duration: Dec 2 1997 → Dec 4 1997