data_global _chemical_name_mineral 'Boracite' loop_ _publ_author_name 'Dowty E' 'Clark J R' _journal_name_full 'Zeitschrift fur Kristallographie' _journal_volume 138 _journal_year 1973 _journal_page_first 64 _journal_page_last 99 _publ_section_title ; Crystal-structure refinements for orthorhombic boracite, Mg3B7O13Cl, and a trigonal, iron-rich analogue Note: [.25 .25 0] added to all atoms to move origin to screw axis ; _database_code_amcsd 0010744 _chemical_compound_source 'Solvayshall, Roschwitz, Germany' _chemical_formula_sum 'Mg3 B7 O13 Cl' _cell_length_a 8.5496 _cell_length_b 8.5496 _cell_length_c 12.0910 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 883.800 _exptl_crystal_density_diffrn 2.946 _symmetry_space_group_name_H-M 'P c a 21' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,-y,z' '1/2-x,y,1/2+z' '-x,-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 Mg1 0.24170 0.74880 0.47700 0.00747 Mg2 0.48510 0.97040 0.25370 0.00785 Mg3 0.48500 0.52840 0.25140 0.00747 B11 0.49820 0.99830 0.50180 0.00329 B12 0.25600 0.24870 0.24880 0.00545 B13 0.49810 0.50230 0.50160 0.00583 B21 0.25230 0.40370 0.42020 0.00583 B22 0.25350 0.09640 0.42240 0.00633 B23 0.40530 0.24990 0.57350 0.00633 B3 0.54720 0.75000 0.60120 0.00646 O1 0.26730 0.24930 0.49140 0.00507 O21 0.33240 0.97180 0.47940 0.00431 O22 0.41060 0.46070 0.40190 0.00494 O23 0.32890 0.12530 0.31560 0.00519 O24 0.16430 0.52010 0.48130 0.00519 O25 0.08960 0.05720 0.40590 0.00557 O26 0.17700 0.36530 0.31720 0.00633 O27 0.38300 0.33010 0.18650 0.00481 O28 0.53850 0.91130 0.60660 0.00659 O29 0.53370 0.16290 0.52260 0.00367 O210 0.36090 0.17430 0.67640 0.00418 O211 0.45040 0.40970 0.59650 0.00443 O212 0.45750 0.67060 0.52610 0.00570 Cl 0.27410 0.74940 0.26180 0.01165 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 Mg1 0.00555 0.00481 0.01185 -0.00019 0.00031 -0.00105 Mg2 0.00852 0.00778 0.00741 0.00333 0.00016 -0.00105 Mg3 0.00889 0.00778 0.00592 -0.00333 0.00105 -0.00052 B11 0.00444 0.00259 0.00296 0.00148 -0.00209 -0.00157 B12 0.00444 0.00444 0.00741 -0.00111 -0.00209 0.00157 B13 0.00630 0.00481 0.00815 0.00000 0.00052 0.00105 B21 0.00407 0.00259 0.01111 0.00074 0.00052 0.00367 B22 0.00815 0.00481 0.00000 0.00000 -0.00157 0.00262 B23 0.00518 0.00481 0.00148 0.00259 0.00052 -0.00262 B3 0.00778 0.00444 0.00741 0.00037 -0.00262 0.00052 O1 0.00555 0.00296 0.00667 0.00148 -0.00157 -0.00105 O21 0.00259 0.00481 0.00518 -0.00074 -0.00105 -0.00105 O22 0.00555 0.00667 0.00296 -0.00111 0.00157 0.00105 O23 0.00481 0.00518 0.00592 0.00074 0.00000 0.00105 O24 0.00481 0.00407 0.00667 -0.00037 -0.00052 -0.00157 O25 0.00296 0.00481 0.00889 -0.00148 0.00000 0.00052 O26 0.00630 0.00555 0.00741 0.00185 -0.00105 -0.00105 O27 0.00667 0.00518 0.00296 -0.00185 0.00157 -0.00157 O28 0.00704 0.00222 0.01037 0.00111 0.00000 0.00105 O29 0.00630 0.00296 0.00148 -0.00037 0.00052 -0.00157 O210 0.00592 0.00370 0.00296 0.00148 0.00000 0.00052 O211 0.00592 0.00407 0.00370 -0.00037 -0.00052 0.00000 O212 0.00630 0.00370 0.00667 0.00000 -0.00209 -0.00052 Cl 0.01296 0.01037 0.01185 0.00022 0.00042 -0.00031