data_global
_chemical_name_mineral 'Willemite'
loop_
_publ_author_name
'Klaska K-H'
'Eck J C'
'Pohl D'
_journal_name_full 'Acta Crystallographica, Section B'
_journal_volume 34 
_journal_year 1978
_journal_page_first 3324
_journal_page_last 3325
_publ_section_title
;
 New investigation of willemite
 Note: Anisotropic displacement parameters are from ICSD
;
_database_code_amcsd 0009645
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Zn2 Si O4'
_cell_length_a 13.948
_cell_length_b 13.948
_cell_length_c 9.315
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 1569.413
_exptl_crystal_density_diffrn      4.244
_symmetry_space_group_name_H-M 'R -3'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '2/3+x,1/3+y,1/3+z'
  '1/3+x,2/3+y,2/3+z'
  'y,-x+y,-z'
  '2/3+y,1/3-x+y,1/3-z'
  '1/3+y,2/3-x+y,2/3-z'
  '-x+y,-x,z'
  '2/3-x+y,1/3-x,1/3+z'
  '1/3-x+y,2/3-x,2/3+z'
  '-x,-y,-z'
  '2/3-x,1/3-y,1/3-z'
  '1/3-x,2/3-y,2/3-z'
  '-y,x-y,z'
  '2/3-y,1/3+x-y,1/3+z'
  '1/3-y,2/3+x-y,2/3+z'
  'x-y,x,-z'
  '2/3+x-y,1/3+x,1/3-z'
  '1/3+x-y,2/3+x,2/3-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Zn1   0.98257   0.19167   0.41535
Zn2   0.97694   0.19197   0.08140
Si   0.98393   0.19557   0.74940
O1   0.11040   0.21640   0.75050
O2  -0.00420   0.31780   0.74900
O3   0.91640   0.12560   0.89260
O4   0.92270   0.12830   0.60360
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 0.00658 0.00695 0.00571 0.00325 0.00040 -0.00011
Zn2 0.00695 0.00695 0.00571 0.00340 0.00086 0.00017
Si 0.00303 0.00340 0.00220 0.00185 0.00120 0.00017
O1 0.00591 0.01183 0.00571 0.00739 0.00057 0.00171
O2 0.00813 0.00665 0.01143 0.00370 -0.00342 -0.00057
O3 0.00517 0.00370 0.00703 -0.00222 -0.00057 -0.00057
O4 0.00887 0.00813 0.00527 0.00222 0.00114 0.00285