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 = 1 bar
7.51605 7.51605 16.0759 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 .00498 .00498 .00077       0      0       0
Fe     .25   .25 .0919 .00240 .00240 .00138       0      0       0
Si   .5196 .9354 .1549 .00259 .00262 .00096 -.00004 .00025 -.00025
O1   .4740 .9740   .25  .0144  .0144  .0017  -.0048  .0025  -.0025
O2   .7228 .9966 .1375  .0032  .0088  .0017  -.0005      0   .0007
O3   .3905 .0265 .0902  .0057  .0039  .0026   .0015 -.0020  -.0004