data_global
_chemical_name_mineral 'Hardystonite'
loop_
_publ_author_name
'Warren B'
'Trautz O'
_journal_name_full 'Zeitschrift fur Kristallographie'
_journal_volume 75 
_journal_year 1930
_journal_page_first 525
_journal_page_last 528
_publ_section_title
;
 The Structure of Hardystonite Ca2 Zn Si2 O7
 _cod_database_code 1011252
;
_database_code_amcsd 0018114
_chemical_formula_sum 'Ca2 Si2 Zn O7'
_cell_length_a 7.846
_cell_length_b 7.846
_cell_length_c 5.
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 307.799
_exptl_crystal_density_diffrn      3.385
_symmetry_space_group_name_H-M 'P -4 21 m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2-y,1/2-x,z'
  'y,-x,-z'
  '1/2-x,1/2+y,-z'
  '-x,-y,z'
  '1/2+y,1/2+x,z'
  '-y,x,-z'
  '1/2+x,1/2-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Ca1   0.33000   0.17000  -0.49000
Si1   0.14000   0.36000  -0.05000
Zn1   0.00000   0.00000   0.00000
O1   0.50000   0.00000   0.19000
O2   0.14000   0.36000   0.26000
O3   0.08000   0.18000  -0.19000