data_global _chemical_name_mineral 'Danburite' loop_ _publ_author_name 'Sugiyama K' 'Takeuchi Y' _journal_name_full 'Zeitschrift fur Kristallographie' _journal_volume 173 _journal_year 1985 _journal_page_first 293 _journal_page_last 304 _publ_section_title ; Unusual thermal expansion of a B-O-bond in the structure of danburite CaB2Si2O8 Note: AnisoB's from ICSD Sample: T = 910 C ; _database_code_amcsd 0010951 _chemical_compound_source 'Toroku mine, Miyazaki Prefecture, Japan' _chemical_formula_sum 'Ca B2 Si2 O8' _cell_length_a 8.101 _cell_length_b 8.801 _cell_length_c 7.786 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 555.118 _exptl_crystal_density_diffrn 2.942 _symmetry_space_group_name_H-M 'P n a m' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,y,1/2-z' '-x,-y,1/2+z' '1/2-x,1/2+y,1/2+z' '1/2+x,1/2-y,1/2-z' '1/2+x,1/2-y,z' '1/2-x,1/2+y,-z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Ca 0.38920 0.07680 0.25000 0.02948 B 0.26190 0.41860 0.41970 0.01788 Si 0.05564 0.19260 -0.05649 0.01478 O1 0.19440 0.06840 -0.00610 0.02943 O2 0.12810 0.36410 -0.04040 0.02432 O3 0.40320 0.31510 0.07660 0.02384 O4 0.51020 0.66760 0.25000 0.02912 O5 0.18820 0.42500 0.25000 0.02793 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 Ca 0.03291 0.02590 0.02979 -0.00108 0.00000 0.00000 B 0.01862 0.01648 0.01873 -0.00108 -0.00032 -0.00104 Si 0.01662 0.01264 0.01505 -0.00029 -0.00022 -0.00073 O1 0.03158 0.01884 0.03808 0.00939 -0.00735 -0.00555 O2 0.02892 0.01530 0.02856 -0.00542 -0.00991 0.00174 O3 0.02228 0.02590 0.02027 0.00614 0.00607 0.00278 O4 0.03724 0.03492 0.01536 0.00867 0.00000 0.00000 O5 0.02261 0.04552 0.01566 0.00686 0.00000 0.00000