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 ; _database_code_amcsd 285 _chemical_formula_sum 'Al Si2 O6 H' _cell_length_a 5.1614 _cell_length_b 8.9576 _cell_length_c 9.3511 _cell_angle_alpha 91.03 _cell_angle_beta 100.37 _cell_angle_gamma 89.75 _cell_volume 425.206 _exptl_crystal_density_diffrn 2.814 _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 0.5 0.167 0.0 Si1 0.748 0.0 0.289 Si2 0.759 0.331 0.289 O1 0.671 0.004 0.113 O2 0.721 0.319 0.113 O-H 0.221 0.186 0.113 Ob1 0.055 0.387 0.353 Ob2 0.724 0.167 0.353 Ob3 0.55 0.448 0.336