data_global _chemical_name_mineral 'Pyrophyllite' loop_ _publ_author_name 'Wardle R' 'Brindley G W' _journal_name_full 'American Mineralogist' _journal_volume 57 _journal_year 1972 _journal_page_first 732 _journal_page_last 750 _publ_section_title ; The crystal structures of pyrophyllite, 1Tc, and of its dehydroxylate Note: this is polytype pyrophyllite-1Tc ; _database_code_amcsd 286 _chemical_formula_sum 'Al2 Si4 O11' _cell_length_a 5.1919 _cell_length_b 9.1224 _cell_length_c 9.499 _cell_angle_alpha 91.17 _cell_angle_beta 100.21 _cell_angle_gamma 88.62 _cell_volume 442.585 _exptl_crystal_density_diffrn 2.569 _symmetry_space_group_name_H-M 'C -1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' '-x,-y,-z' '1/2-x,1/2-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Al 0.552 0.149 0.0 Si1 0.225 0.486 0.286 Si2 0.749 0.312 0.286 O1 0.25 0.25 0.0 O2 0.123 0.492 0.115 O3 0.728 0.292 0.115 O4 0.037 0.378 0.355 O5 0.717 0.152 0.355 O6 0.522 0.425 0.32