Sillimanite
Winter J K, Ghose S
American Mineralogist 64 (1979) 573-586
Thermal expansion and high-temperature crystal chemistry of the Al2SiO5 polymorphs
T = 1000 deg C
_database_code_amcsd 0000727
7.503 7.739 5.804 90 90 90 Pbnm
atom     x     y     z B(1,1) B(2,2) B(3,3) B(1,2) B(1,3) B(2,3)
Al1      0     0     0 0.0050 0.0062 0.0090  .0000 -.0002 -.0002
Al2  .1410 .3463   .25 0.0052 0.0065 0.0096 -.0003      0      0
Si   .1520 .3413   .75 0.0044 0.0057 0.0088 -.0007      0      0
O1   .3596 .4106   .75 0.0052 0.0083 0.0117 -.0024      0      0
O2   .3566 .4363   .25 0.0051 0.0095 0.0102 -.0021      0      0
O3   .4783 .0006   .75 0.0129 0.0112 0.0259 -.0072      0      0
O4   .1248 .2249 .5142 0.0091 0.0062 0.0094 -.0022 -.0006 -.0001