Klug D.D., Rousseau R., Uehara K., Bernasconi M., Tse J.S.
National Research Council of Canada, CA
Keywords: ab initio calculations, Car-Parrinello, high-pressure, SiO2
The mechanism for the pressure induced transformation of cristobalite to stishovite and post-stishovite phases has been obtained from constant pressure ab initio molecular dynamics simulations. The cristobalite to stishovite transformation is found to be a two step process where SiO4 tetrahedra first rotate followed by a lattice distortion to yield the 6-coordinated stishovite structure. Further compression of stishovite yields the CaCl2 structure and is followed by another 6-coordinated structure with symmetry P21/n (at 11 Mbar) which remains stable to a pressure of about 14 Mbar and then transforms into a 9-coordinated P21/m structure.
Journal: TechConnect Briefs
Volume: 2, Technical Proceedings of the 2001 International Conference on Computational Nanoscience and Nanotechnology
Published: March 19, 2001
Pages: 129 - 132
Industry sector: Advanced Materials & Manufacturing
Topic: Informatics, Modeling & Simulation
ISBN: 0-9708275-3-9