data_global
_chemical_name_mineral 'Sillimanite'
loop_
_publ_author_name
'Winter J K'
'Ghose S'
_journal_name_full 'American Mineralogist'
_journal_volume 64 
_journal_year 1979
_journal_page_first 573
_journal_page_last 586
_publ_section_title
;
 Thermal expansion and high-temperature crystal chemistry of the Al2SiO5 polymorphs
 T = 25 deg C
;
_database_code_amcsd 0000723
_chemical_formula_sum 'Al2 Si O5'
_cell_length_a 7.4883
_cell_length_b 7.6808
_cell_length_c 5.7774
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 332.294
_exptl_crystal_density_diffrn      3.239
_symmetry_space_group_name_H-M 'P b n m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,y,1/2-z'
  '-x,-y,1/2+z'
  '1/2+x,1/2-y,1/2+z'
  '1/2-x,1/2+y,1/2-z'
  '1/2-x,1/2+y,z'
  '1/2+x,1/2-y,-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Al1   0.00000   0.00000   0.00000
Al2   0.14170   0.34490   0.25000
Si   0.15330   0.34020   0.75000
O1   0.36050   0.40940   0.75000
O2   0.35690   0.43410   0.25000
O3   0.47630   0.00150   0.75000
O4   0.12520   0.22300   0.51450
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
Al1 0.00256 0.00568 0.00693 -0.00029 0.00000 -0.00022
Al2 0.00341 0.00717 0.00761 -0.00029 0.00000 0.00000
Si 0.00227 0.00568 0.00761 -0.00058 0.00000 0.00000
O1 0.00341 0.00807 0.00930 -0.00146 0.00000 0.00000
O2 0.00341 0.00986 0.00795 -0.00117 0.00000 0.00000
O3 0.00852 0.00986 0.01505 -0.00466 0.00000 0.00000
O4 0.00625 0.00747 0.00744 -0.00146 0.00000 0.00000