data_global _chemical_name_mineral 'Sillimanite' loop_ _publ_author_name 'Yang H' 'Hazen R M' 'Finger L W' 'Prewitt C T' 'Downs R T' _journal_name_full 'Physics and Chemistry of Minerals' _journal_volume 25 _journal_year 1997 _journal_page_first 39 _journal_page_last 47 _publ_section_title ; Compressibility and crystal structure of sillimanite, Al2SiO5, at high pressure Sample: P = 3.72 GPa ; _database_code_amcsd 0008110 _chemical_formula_sum 'Al2 Si O5' _cell_length_a 7.4345 _cell_length_b 7.5989 _cell_length_c 5.7507 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 324.880 _exptl_crystal_density_diffrn 3.313 _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 _atom_site_U_iso_or_equiv Al1 0.00000 0.00000 0.00000 0.00393 Al2 0.14090 0.34340 0.25000 0.00494 Si 0.15430 0.33890 0.75000 0.00545 OA 0.36200 0.40600 0.75000 0.00684 OB 0.35590 0.43340 0.25000 0.00646 OC 0.47450 0.00280 0.75000 0.00988 OD 0.12660 0.22110 0.51520 0.00646