data_global _chemical_name_mineral 'Cordierite' loop_ _publ_author_name 'Armbruster T' _journal_name_full 'American Mineralogist' _journal_volume 71 _journal_year 1986 _journal_page_first 746 _journal_page_last 757 _publ_section_title ; Role of Na in the structure of low-cordierite: A single-crystal X-ray study Sample: from Alpe Sponda, Central Alps, Switzerland ; _database_code_amcsd 0001017 _chemical_formula_sum 'O18.6 Al3.84 Be.16 Si5 (Mg1.4 Fe.6) Na.25 H.6' _cell_length_a 17.060 _cell_length_b 9.759 _cell_length_c 9.322 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 1552.006 _exptl_crystal_density_diffrn 2.640 _symmetry_space_group_name_H-M 'C c c m' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,1/2+z' '1/2+x,1/2-y,1/2+z' '-x,y,1/2-z' '1/2-x,1/2+y,1/2-z' '-x,y,1/2+z' '1/2-x,1/2+y,1/2+z' 'x,-y,1/2-z' '1/2+x,1/2-y,1/2-z' 'x,y,-z' '1/2+x,1/2+y,-z' '-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 _atom_site_occupancy O11 0.24614 -0.10433 0.35857 1.00000 O16 0.06196 -0.41577 0.34876 1.00000 O13 -0.17344 -0.30866 0.35804 1.00000 O26 0.04328 -0.24612 0.00000 1.00000 O21 0.12039 0.18225 0.00000 1.00000 O23 0.16356 -0.07844 0.00000 1.00000 Al11 0.25000 0.25000 0.25010 0.92000 Be11 0.25000 0.25000 0.25010 0.08000 Si16 0.00000 0.50000 0.25000 1.00000 Si21 0.19177 0.07870 0.00000 1.00000 Si23 -0.13562 0.23649 0.00000 1.00000 Al26 0.05051 0.30825 0.00000 1.00000 Mg 0.33632 0.00000 0.25000 0.70000 Fe 0.33632 0.00000 0.25000 0.30000 NaCh0 0.00000 0.00000 0.00000 0.25000 O-HCh1 0.00000 0.00000 0.25000 0.60000 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 O11 0.01180 0.00860 0.00940 -0.00050 0.00290 -0.00090 O16 0.00740 0.01130 0.00940 -0.00080 0.00000 -0.00330 O13 0.01000 0.01050 0.00950 0.00160 -0.00110 -0.00260 O26 0.00590 0.01630 0.01960 -0.00210 0.00000 0.00000 O21 0.01190 0.01270 0.01870 0.00580 0.00000 0.00000 O23 0.01360 0.00650 0.01920 -0.00310 0.00000 0.00000 Al11 0.00830 0.00680 0.00780 0.00120 0.00000 0.00000 Be11 0.00830 0.00680 0.00780 0.00120 0.00000 0.00000 Si16 0.00630 0.00720 0.00620 0.00000 0.00000 0.00000 Si21 0.00620 0.00500 0.00740 0.00020 0.00000 0.00000 Si23 0.00560 0.00580 0.00760 -0.00050 0.00000 0.00000 Al26 0.00580 0.00620 0.00680 0.00050 0.00000 0.00000 Mg 0.00860 0.01120 0.01120 0.00020 0.00000 0.00000 Fe 0.00860 0.01120 0.01120 0.00020 0.00000 0.00000 NaCh0 0.03300 0.02200 0.04900 0.00300 0.00000 0.00000 O-HCh1 0.10900 0.05400 0.05400 0.00000 0.00000 0.00000