Cristobalite II Dera P, Lazarz J D, Prakapenka V B, Barkley M, Downs R T Physics and Chemistry of Minerals 38 (2011) 517-529 New insights into the high-pressure polymorphism of SiO2 cristobalite Note: P = 3.5 GPa, data transformed from Dove et al (2000) _database_code_amcsd 0018348 8.011 4.544 8.890 90 121.0 90 P2_1/c atom x y z Uiso Si1 .6274 .2661 .8461 .018 Si2 .8660 .0221 .7189 .018 O1 .8152 .1255 .8517 .028 O2 .6944 .4046 .0275 .028 O3 .4637 .0262 .7952 .028 O4 .0696 .1948 .7604 .028