Sillimanite
Winter J K, Ghose S
American Mineralogist 64 (1979) 573-586
Thermal expansion and high-temperature crystal chemistry of the Al2SiO5 polymorphs
T = 25 deg C
_database_code_amcsd 0000723
7.4883 7.6808 5.7774 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 0.0009 0.0019 0.0041 -.0001  .0000 -.0001
Al2  .1417 .3449   .25 0.0012 0.0024 0.0045 -.0001      0      0
Si   .1533 .3402   .75 0.0008 0.0019 0.0045 -.0002      0      0
O1   .3605 .4094   .75 0.0012 0.0027 0.0055 -.0005      0      0
O2   .3569 .4341   .25 0.0012 0.0033 0.0047 -.0004      0      0
O3   .4763 .0015   .75 0.0030 0.0033 0.0089 -.0016      0      0
O4   .1252 .2230 .5145 0.0022 0.0025 0.0044 -.0005  .0000  .0000