data_global
_chemical_name_mineral 'Huntite'
loop_
_publ_author_name
'Dollase W A'
'Reeder R J'
_journal_name_full 'American Mineralogist'
_journal_volume 71 
_journal_year 1986
_journal_page_first 163
_journal_page_last 166
_publ_section_title
;
 Crystal structure refinement of huntite, CaMg3(CO3)4, with X-ray powder data
;
_database_code_amcsd 0001006
_chemical_formula_sum 'Ca Mg3 C4 O12'
_cell_length_a 9.5027
_cell_length_b 9.5027
_cell_length_c 7.8212
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 611.643
_exptl_crystal_density_diffrn      2.875
_symmetry_space_group_name_H-M 'R 3 2'
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'
  '-x,-x+y,-z'
  '2/3-x,1/3-x+y,1/3-z'
  '1/3-x,2/3-x+y,2/3-z'
  'y,x,-z'
  '2/3+y,1/3+x,1/3-z'
  '1/3+y,2/3+x,2/3-z'
  'x-y,-y,-z'
  '2/3+x-y,1/3-y,1/3-z'
  '1/3+x-y,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
_atom_site_U_iso_or_equiv
Ca   0.00000   0.00000   0.00000   0.01191
Mg   0.54430   0.00000   0.00000   0.01191
C1   0.00000   0.00000   0.50000   0.01191
C2   0.45350   0.00000   0.50000   0.01191
O1   0.86630   0.00000   0.50000   0.01191
O2   0.58950   0.00000   0.50000   0.01191
O3   0.45690   0.13550   0.51610   0.01191