data_global
_chemical_name_mineral 'Bechererite'
loop_
_publ_author_name
'Hoffmann C'
'Armbruster T'
'Giester G'
_journal_name_full 'American Mineralogist'
_journal_volume 82 
_journal_year 1997
_journal_page_first 1014
_journal_page_last 1018
_publ_section_title
;
 The acentric structure (P3) of bechererite, Zn7Cu(OH)13[SiO(OH)3SO4]
 Note U(1,2) for Zn2, Zn21, and O1 changed to match symmetry constraints.
;
_database_code_amcsd 0001950
_chemical_formula_sum 'Zn8 S Si H12 O23'
_cell_length_a 8.319
_cell_length_b 8.319
_cell_length_c 7.377
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 442.133
_exptl_crystal_density_diffrn      3.618
_symmetry_space_group_name_H-M 'P 3'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-y,x-y,z'
  '-x+y,-x,z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Zn1   0.13260   0.41360   0.99970 ?
Zn11   0.86280   0.57340   0.00070 ?
Zn2   0.00000   0.00000   0.24690 ?
Zn21   0.00000   0.00000   0.75710 ?
S   0.33333   0.66667   0.59020 ?
Si   0.66667   0.33333   0.39260 ?
H4   0.87700   0.24800   0.21200   0.03002
H41   0.05000   0.74800   0.72900   0.03002
H5   0.34700   0.50000   0.24500   0.03002
H51   0.63000   0.58700   0.76400   0.03002
O1   0.33333   0.66667   0.79000 ?
O11   0.66667   0.33333   0.16300 ?
O2   0.17100   0.67560   0.52300 ?
O21   0.85360   0.33400   0.47800 ?
O4   0.94350   0.18670   0.16800 ?
O41   0.05230   0.80450   0.83900 ?
O5   0.37520   0.48260   0.12600 ?
O51   0.62880   0.52840   0.87300 ?
O3   0.05100   0.06000   0.50100   0.01900
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
Zn1 0.01130 0.01250 0.02930 0.00760 -0.00070 -0.00140
Zn11 0.00960 0.01170 0.02930 0.00540 -0.00170 -0.00140
Zn2 0.01810 0.01810 0.02000 0.00905 0.00000 0.00000
Zn21 0.01330 0.01330 0.02000 0.00665 0.00000 0.00000
S 0.01600 0.01600 0.01800 0.00800 0.00000 0.00000
Si 0.01200 0.01200 0.01700 0.00600 0.00000 0.00000
O1 0.02700 0.02700 0.01300 0.01350 0.00000 0.00000
O11 0.02000 0.02000 0.02800 0.01000 0.00000 0.00000
O2 0.02800 0.03900 0.02000 0.02400 -0.00500 -0.00400
O21 0.03500 0.06500 0.03500 0.02600 -0.00200 -0.01200
O4 0.01300 0.02600 0.02300 0.00800 -0.00300 -0.00900
O41 0.01700 0.01500 0.02600 0.01100 0.00400 0.00600
O5 0.01200 0.01800 0.02100 0.00800 0.00200 -0.00400
O51 0.01400 0.01500 0.01900 0.01000 0.00000 0.00300