Phase-A
Horiuchi H, Morimoto N, Yamamoto K, Akimoto S I
American Mineralogist 64 (1979) 593-598
Crystal structure of 2Mg2SiO4.3Mg(OH)2, a new high-pressure structure type
_database_code_amcsd 0000737
7.8603 7.8603 9.5730 90 90 120 P6_3
atom     x     y     z  B(1,1)  B(2,2)  B(3,3)  B(1,2)  B(1,3)  B(2,3)
Mg1  .3722 .4547 .3857 0.00289 0.00292 0.00145 0.00125 -.00047 0.00005
Mg2  .2252 .2438 .1127 0.00291 0.00242 0.00126 0.00127 -.00039 -.00033
Mg3    1/3   2/3 .1029 0.00283 0.00283 0.00133 0.00142       0       0
Si1    2/3   1/3 .1741 0.00196 0.00196 0.00073 0.00098       0       0
Si2      0     0 .4018 0.00204 0.00204 0.00070 0.00102       0       0
O1   .2001 .0274 -.024 0.00251 0.00240 0.00118 0.00118 -.00006 -.00010
O2   .4766 .0988 .4844 0.00320 0.00268 0.00136 0.00149 0.00004 -.00012
O3   .4538 .2947 .2320 0.00219 0.00401 0.00136 0.00164 -.00016 -.00007
O4   .1704 .4367 .2398 0.00293 0.00280 0.00176 0.00145 0.00021 0.00023
O5     2/3   1/3     0 0.00279 0.00279 0.00120 0.00139       0       0
O6       0     0 .2323 0.00366 0.00366 0.00055 0.00183       0       0