data_global
_chemical_name_mineral 'Chkalovite'
loop_
_publ_author_name
'Pyatenko Y A'
'Bokii G B'
'Belov N V'
_journal_name_full 'Doklady Akademii Nauk SSSR'
_journal_volume 108 
_journal_year 1956
_journal_page_first 1077
_journal_page_last 1080
_publ_section_title
;
 The X-ray analysis of the crystal structure of chkalovite
;
_database_code_amcsd 0012436
_chemical_formula_sum 'Be Si2 Na2 O6'
_cell_length_a 21.1
_cell_length_b 21.1
_cell_length_c 6.87
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 3058.593
_exptl_crystal_density_diffrn      2.699
_symmetry_space_group_name_H-M 'F d d d'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,1/2+y,1/2+z'
  '1/2+x,y,1/2+z'
  '1/2+x,1/2+y,z'
  '3/4+x,1/4-y,3/4+z'
  '3/4+x,3/4-y,1/4+z'
  '1/4+x,1/4-y,1/4+z'
  '1/4+x,3/4-y,3/4+z'
  '-x,y,-z'
  '-x,1/2+y,1/2-z'
  '1/2-x,y,1/2-z'
  '1/2-x,1/2+y,-z'
  '1/4-x,3/4+y,3/4+z'
  '1/4-x,1/4+y,1/4+z'
  '3/4-x,3/4+y,1/4+z'
  '3/4-x,1/4+y,3/4+z'
  'x,-y,-z'
  'x,1/2-y,1/2-z'
  '1/2+x,-y,1/2-z'
  '1/2+x,1/2-y,-z'
  '3/4+x,3/4+y,1/4-z'
  '3/4+x,1/4+y,3/4-z'
  '1/4+x,3/4+y,3/4-z'
  '1/4+x,1/4+y,1/4-z'
  '-x,-y,z'
  '-x,1/2-y,1/2+z'
  '1/2-x,-y,1/2+z'
  '1/2-x,1/2-y,z'
  '1/4-x,1/4-y,1/4-z'
  '1/4-x,3/4-y,3/4-z'
  '3/4-x,1/4-y,3/4-z'
  '3/4-x,3/4-y,1/4-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Be1   0.00000   0.00000   0.00000
Be2   0.00000   0.33000   0.00000
Si1   0.34600   0.00000   0.00000
Si2   0.07100   0.09300   0.25000
Na1   0.15400   0.00000   0.00000
Na2   0.07100   0.09300   0.75000
O1   0.12500   0.12500   0.12500
O2   0.04000   0.03000   0.16000
O3   0.03000   0.13000   0.37000
O4   0.13000   0.06000   0.37000
O5   0.20000   0.04000   0.66000