data_global _chemical_name_mineral 'Montmorillonite' loop_ _publ_author_name 'Viani A' 'Gualtieri A' 'Artioli G' _journal_name_full 'American Mineralogist' _journal_volume 87 _journal_year 2002 _journal_page_first 966 _journal_page_last 975 _publ_section_title ; The nature of disorder in montmorillonite by simulation of X-ray powder patterns Note: Structural simulation model ; _database_code_amcsd 0002868 _chemical_formula_sum 'Al2 Si4 O12 Ca.5' _cell_length_a 5.18 _cell_length_b 8.98 _cell_length_c 15.00 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 697.746 _exptl_crystal_density_diffrn 1.801 _symmetry_space_group_name_H-M 'P 1' loop_ _space_group_symop_operation_xyz 'x,y,z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_U_iso_or_equiv Al 0.87530 0.33300 0.22140 1.00000 0.02000 Al 0.87530 0.66700 0.22140 1.00000 0.02000 Al 0.37530 0.83300 0.22140 1.00000 0.02000 Al 0.37530 0.16700 0.22140 1.00000 0.02000 Si 0.55880 0.32900 0.04300 1.00000 0.02000 Si 0.55880 0.67100 0.04300 1.00000 0.02000 Si 0.69190 0.82900 0.39990 1.00000 0.02000 Si 0.69190 0.17100 0.39990 1.00000 0.02000 Si 0.05880 0.82900 0.04300 1.00000 0.02000 Si 0.05880 0.17100 0.04300 1.00000 0.02000 Si 0.19190 0.32900 0.39990 1.00000 0.02000 Si 0.19190 0.67100 0.39990 1.00000 0.02000 O 0.51340 0.50000 0.00990 1.00000 0.02000 O 0.82800 0.72800 0.00000 1.00000 0.02000 O 0.82800 0.27200 0.00000 1.00000 0.02000 O 0.49540 0.00000 0.15200 1.00000 0.02000 O 0.56820 0.69100 0.14870 1.00000 0.02000 O 0.57220 0.30900 0.14870 1.00000 0.02000 O 0.73730 0.00000 0.43290 1.00000 0.02000 O 0.42270 0.22800 0.44280 1.00000 0.02000 O 0.42270 0.77200 0.44280 1.00000 0.02000 O 0.75530 0.50000 0.29080 1.00000 0.02000 O 0.68240 0.19100 0.29410 1.00000 0.02000 O 0.67840 0.80900 0.29410 1.00000 0.02000 O 0.01340 0.00000 0.00990 1.00000 0.02000 O 0.32800 0.22800 0.00000 1.00000 0.02000 O 0.32800 0.77200 0.00000 1.00000 0.02000 O 0.99540 0.50000 0.15200 1.00000 0.02000 O 0.06820 0.19100 0.14870 1.00000 0.02000 O 0.07220 0.80900 0.14870 1.00000 0.02000 O 0.23730 0.50000 0.43290 1.00000 0.02000 O 0.92270 0.72800 0.44280 1.00000 0.02000 O 0.92270 0.27200 0.44280 1.00000 0.02000 O 0.25530 0.00000 0.29080 1.00000 0.02000 O 0.18240 0.69100 0.29410 1.00000 0.02000 O 0.17840 0.30900 0.29410 1.00000 0.02000 Ca 0.18930 0.00000 0.72150 0.50000 0.02000 Ca 0.68930 0.50000 0.72150 0.50000 0.02000