data_global _chemical_name_mineral 'Sillimanite' loop_ _publ_author_name 'Burt J B' 'Ross N L' 'Angel R J' 'Koch M' _journal_name_full 'American Mineralogist' _journal_volume 91 _journal_year 2006 _journal_page_first 319 _journal_page_last 326 _publ_section_title ; Equations of state and structures of andalusite to 9.8 GPa and sillimanite to 8.5 GPa Sample: P = 5.750 GPa ; _database_code_amcsd 0004112 _chemical_compound_source 'Okkamitiya Sabaragamuiwa province, Sri Lanka' _chemical_formula_sum 'Al2 Si O5' _cell_length_a 7.39939 _cell_length_b 7.5576 _cell_length_c 5.73421 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 320.666 _exptl_crystal_density_diffrn 3.357 _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 0.00355 Al2 0.14001 0.33780 0.25000 0.00393 Si 0.15466 0.33630 0.75000 0.00355 OA 0.36390 0.41420 0.75000 0.00519 OB 0.35450 0.44520 0.25000 0.00532 OC 0.47380 0.00470 0.75000 0.01077 OD 0.12750 0.21620 0.51540 0.00595