Sillimanite Peterson R C, McMullan R K American Mineralogist 71 (1986) 742-745 Neutron diffraction studies of sillimanite _database_code_amcsd 0001016 7.479 7.670 5.769 90 90 90 Pbnm atom x y z occ U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) Al1 0 0 0 .987 .0031 .0047 .0034 .0001 -.0003 .0001 Fe1 0 0 0 .013 .0031 .0047 .0034 .0001 -.0003 .0001 Al2 .1418 .3449 .25 .993 .0039 .0058 .0043 -.0002 0 0 Fe2 .1418 .3449 .25 .007 .0039 .0058 .0043 -.0002 0 0 Si .1535 .3402 .75 .0030 .0049 .0037 -.0004 0 0 OA .3600 .4088 .75 .0035 .0072 .0058 -.0016 0 0 OB .3563 .4340 .25 .0038 .0072 .0053 -.0013 0 0 OC .4765 .0017 .75 .0090 .0100 .0111 -.0050 0 0 OD .1256 .2232 .5144 .0061 .0056 .0045 -.0015 -.0002 -.0002