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
 Note: x(B) corrected to match reported bond lengths
 Sample: T = 817 C
;
_database_code_amcsd 0010950
_chemical_compound_source 'Toroku mine, Miyazaki Prefecture, Japan'
_chemical_formula_sum 'Ca B2 Si2 O8'
_cell_length_a 8.092
_cell_length_b 8.796
_cell_length_c 7.7768
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 553.531
_exptl_crystal_density_diffrn      2.950
_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   0.38890   0.07680   0.25000   0.02694
B   0.26140   0.41910   0.42000   0.01649
Si   0.05545   0.19272  -0.05656   0.01339
O1   0.19420   0.06810  -0.00550   0.02695
O2   0.12790   0.36420  -0.04100   0.02282
O3   0.40310   0.31500   0.07680   0.02158
O4   0.51080   0.66780   0.25000   0.02742
O5   0.18780   0.42560   0.25000   0.02601
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 0.03052 0.02430 0.02604 -0.00108 0.00000 0.00000
B 0.01725 0.01725 0.01471 -0.00072 0.00032 0.00035
Si 0.01526 0.01231 0.01256 -0.00050 0.00022 -0.00069
O1 0.02787 0.01881 0.03401 0.00901 -0.00701 -0.00451
O2 0.02587 0.01607 0.02666 -0.00541 -0.00956 0.00139
O3 0.02024 0.02548 0.01869 0.00577 0.00446 0.00277
O4 0.03417 0.03567 0.01226 0.00757 0.00000 0.00000
O5 0.02057 0.04586 0.01164 0.00685 0.00000 0.00000