Quartz Glinnemann J, King H E, Schulz H, Hahn T, La Placa S J, Dacol F Zeitschrift fur Kristallographie 198 (1992) 177-212 Crystal structures of the low-temperature quartz-type phases of SiO2 and GeO2 at elevated pressure P = 4.0 GPa _database_code_amcsd 0011008 4.775 4.775 5.3046 90 90 120 *P3_121 0 0 .3333333333333333 atom x y z U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) Si .4570 0 0 .0012 .0020 .0069 .0010 .0001 .0002 O .4080 .2881 -.1033 .017 .0090 .011 .010 .003 .001