data_global
_chemical_name_mineral 'Gerstmannite'
loop_
_publ_author_name
'Moore P B'
'Araki T'
_journal_name_full 'American Mineralogist'
_journal_volume 62 
_journal_year 1977
_journal_page_first 51
_journal_page_last 59
_publ_section_title
;
 Gerstmannite, a new zinc silicate mineral and a novel cubic close-packed oxide
 structure
;
_database_code_amcsd 0000554
_chemical_formula_sum 'Mn.786 Mg1.214 Zn Si (O6 H2)'
_cell_length_a 8.185
_cell_length_b 18.650
_cell_length_c 6.256
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 954.980
_exptl_crystal_density_diffrn      3.675
_symmetry_space_group_name_H-M 'B b c m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,y,1/2+z'
  '1/2-x,1/2+y,z'
  '-x,1/2+y,1/2+z'
  '1/2+x,1/2-y,-z'
  '+x,1/2-y,1/2-z'
  'x,y,-z'
  '1/2+x,y,1/2-z'
  '-x,-y,z'
  '1/2-x,-y,1/2+z'
  '1/2+x,1/2-y,z'
  '+x,1/2-y,1/2+z'
  '1/2-x,1/2+y,-z'
  '-x,1/2+y,1/2-z'
  '-x,-y,-z'
  '1/2-x,-y,1/2-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Mn   0.00720   0.39590   0.50000   0.78600
Mg   0.00720   0.39590   0.50000   0.21400
Mg   0.25000   0.50000   0.25000   1.00000
Zn   0.40030   0.25000   0.25000   1.00000
Si   0.14420   0.34580   0.00000   1.00000
O-H1   0.00000   0.50000   0.28220   1.00000
O-H2   0.25010   0.43060   0.50000   1.00000
O1   0.24840   0.42050   0.00000   1.00000
O2   0.27750   0.27930   0.00000   1.00000
O3   0.02940   0.33730   0.21120   1.00000
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
Mn 0.00977 0.01092 0.00940 0.00000 0.00000 0.00000
Mg 0.00977 0.01092 0.00940 0.00000 0.00000 0.00000
Mg 0.01490 0.00863 0.00956 0.00008 -0.00278 0.00053
Zn 0.01344 0.00828 0.00866 0.00000 0.00000 0.00053
Si 0.00930 0.00687 0.00896 -0.00046 0.00000 0.00000
O-H1 0.00652 0.00916 0.01229 0.00070 0.00000 0.00000
O-H2 0.01439 0.01004 0.00781 -0.00070 0.00000 0.00000
O1 0.01246 0.00493 0.01174 -0.00224 0.00000 0.00000
O2 0.01459 0.01110 0.00958 0.00711 0.00000 0.00000
O3 0.01398 0.00881 0.01410 -0.00108 0.00553 -0.00207