data_global _chemical_name_mineral 'Braunite' loop_ _publ_author_name 'Miletich R' 'Allan D R' 'Angel R J' _journal_name_full 'Physics and Chemistry of Minerals' _journal_volume 25 _journal_year 1998 _journal_page_first 183 _journal_page_last 192 _publ_section_title ; Structural control of polyhedral compression in synthetic braunite, Mn2+Mn3+6O8SiO4 Sample: P = 2.66 GPa ; _database_code_amcsd 0008126 _chemical_formula_sum 'Mn7 Si O12' _cell_length_a 9.3786 _cell_length_b 9.3786 _cell_length_c 18.6234 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 1638.080 _exptl_crystal_density_diffrn 4.903 _symmetry_space_group_name_H-M 'I 41/a c d' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' '1/4-y,3/4-x,3/4+z' '3/4-y,1/4-x,1/4+z' '1/4+y,3/4+x,3/4-z' '3/4+y,1/4+x,1/4-z' '1/4+y,3/4-x,1/4-z' '3/4+y,1/4-x,3/4-z' '1/4-y,3/4+x,1/4+z' '3/4-y,1/4+x,3/4+z' '1/2+x,-y,z' '+x,1/2-y,1/2+z' '1/2-x,y,-z' '-x,1/2+y,1/2-z' '1/2+x,y,1/2-z' '+x,1/2+y,-z' '1/2-x,-y,1/2+z' '-x,1/2-y,+z' '1/4+y,1/4+x,1/4+z' '3/4+y,3/4+x,3/4+z' '1/4-y,1/4-x,1/4-z' '3/4-y,3/4-x,3/4-z' '1/4-y,1/4+x,3/4-z' '3/4-y,3/4+x,1/4-z' '1/4+y,1/4-x,3/4+z' '3/4+y,3/4-x,1/4+z' '-x,y,1/2+z' '1/2-x,1/2+y,+z' 'x,-y,1/2-z' '1/2+x,1/2-y,-z' '-x,-y,-z' '1/2-x,1/2-y,1/2-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Mn1 0.00000 0.25000 0.12500 0.01494 Mn2 0.00000 0.00000 0.00000 0.01140 Mn3 0.25000 0.21589 0.00000 0.01102 Mn4 0.23263 0.48263 0.12500 0.01064 Si 0.00000 0.25000 0.37500 0.01191 O1 0.14971 0.85484 0.94579 0.01165 O2 0.14422 0.07201 0.05673 0.01317 O3 0.07885 0.13328 0.92554 0.01393 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 Mn1 0.01569 0.01569 0.01353 -0.00450 0.00000 0.00000 Mn2 0.01074 0.01136 0.01212 -0.00192 0.00080 0.00035 Mn3 0.01056 0.01016 0.01248 0.00000 0.00106 0.00000 Mn4 0.01007 0.01007 0.01160 -0.00071 0.00142 0.00142 Si 0.01118 0.01118 0.01353 0.00000 0.00000 0.00000