data_global
_chemical_name_mineral 'Barbertonite'
loop_
_publ_author_name
'Mills S J'
'Whitfield P S'
'Wilson S A'
'Woodhouse J N'
'Dipple G M'
'Raudsepp M'
'Francis C A'
_journal_name_full 'American Mineralogist'
_journal_volume 96 
_journal_year 2011
_journal_page_first 179
_journal_page_last 187
_publ_section_title
;
 The crystal structure of stichtite, re-examination of barbertonite, and the
 nature of polytypism in MgCr hydrotalcites
 Note: Sample 84588, 2H1 polytype of stichtite
;
_database_code_amcsd 0018333
_chemical_compound_source 'Barberton, South Africa'
_chemical_formula_sum '(Mg.75 Cr.25) O2.984 H3.224 C.124'
_cell_length_a 3.09689
_cell_length_b 3.09689
_cell_length_c 15.6193
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 129.731
_exptl_crystal_density_diffrn      2.143
_symmetry_space_group_name_H-M 'P 63/m m c'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-x,-x+y,1/2+z'
  'x,x-y,1/2-z'
  '-x+y,-x,1/2-z'
  'x-y,x,1/2+z'
  '-y,-x,z'
  'y,x,-z'
  'y,-x+y,-z'
  '-y,x-y,z'
  'x-y,-y,1/2+z'
  '-x+y,y,1/2-z'
  'x,y,1/2-z'
  '-x,-y,1/2+z'
  'x,x-y,z'
  '-x,-x+y,-z'
  'x-y,x,-z'
  '-x+y,-x,z'
  'y,x,1/2+z'
  '-y,-x,1/2-z'
  '-y,x-y,1/2-z'
  'y,-x+y,1/2+z'
  '-x+y,y,z'
  'x-y,-y,-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_U_iso_or_equiv
Mg   0.00000   0.00000   0.00000   0.75000   0.01013
Cr   0.00000   0.00000   0.00000   0.25000   0.01013
O1   0.33333   0.66667   0.06500   1.00000   0.00811
H1   0.33333   0.66667   0.13100   1.00000   0.00811
Wat2   0.23000  -0.23000   0.25000   0.20400   0.00811
CO3   0.33333   0.66667   0.25000   0.12400   0.00811
O3   0.33333   0.66667   0.25000   0.37200   0.00811