Gillespite
Hazen R M, Finger L W
American Mineralogist 68 (1983) 595-603
High-pressure and high-temperature crystallographic study of the gillespite I-II
phase transition
P = 9 kbar
7.492 7.492 15.943 90 90 90 *P4/ncc
.25 -.25 0
atom     x     y     z B(1,1) B(2,2) B(3,3) B(1,2) B(1,3) B(2,3)
Ba     .25   .75     0 0.0060 0.0060 0.0017      0      0      0
Fe     .25   .25 .0908 0.0032 0.0032 0.0014      0      0      0
Si   .5195 .9365 .1550 0.0029 0.0029 0.0023 -.0005 0.0001 -.0003
O1   .4726 .9726   .25  0.015  0.015  0.007  0.001  0.005  -.005
O2   .7232 .9978 .1358 0.0030 0.0099 0.0042 -.0009 -.0005 0.0016
O3   .3907 .0292 .0926 0.0085 0.0060 0.0001 0.0009 -.0023 0.0007