data_global
_amcsd_formula_title 'Ba3 O21 Ta3.2 Ti5'
loop_
_publ_author_name
'Mercey C'
'Groult D'
'Raveau B'
_journal_name_full 'Revue de Chimie Minerale'
_journal_volume 16 
_journal_year 1979
_journal_page_first 165
_journal_page_last 173
_publ_section_title
;
 Insertion du niobium et du tantale dans les oxydes de type A3 M8
 O21. Les composes Ba3 M4-4x Ti4+5x O21 (0 <= x <= 0.3)
 _cod_database_code 1001304
;
_database_code_amcsd 0015386
_chemical_formula_sum 'Ba3 Ta3.2 Ti5 O21'
_cell_length_a 9.017
_cell_length_b 9.017
_cell_length_c 11.820
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 832.285
_exptl_crystal_density_diffrn      6.250
_symmetry_space_group_name_H-M 'P 63/m c m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-x,-x+y,z'
  'x,x-y,-z'
  '-x+y,-x,1/2-z'
  'x-y,x,1/2+z'
  '-y,-x,1/2+z'
  'y,x,1/2-z'
  'y,-x+y,-z'
  '-y,x-y,z'
  'x-y,-y,z'
  '-x+y,y,-z'
  'x,y,1/2-z'
  '-x,-y,1/2+z'
  'x,x-y,1/2+z'
  '-x,-x+y,1/2-z'
  'x-y,x,-z'
  '-x+y,-x,z'
  'y,x,z'
  '-y,-x,-z'
  '-y,x-y,1/2-z'
  'y,-x+y,1/2+z'
  '-x+y,y,1/2+z'
  'x-y,-y,1/2-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Ba1   0.59600   0.00000   0.25000   1.00000
Ta1   0.24600   0.00000   0.09500   0.37500
Ti1   0.24600   0.00000   0.09500   0.62500
Ta2   0.33333   0.66667   0.00000   0.37500
Ti2   0.33333   0.66667   0.00000   0.62500
Ta3   0.00000   0.00000   0.25000   0.20000
O1   0.21200   0.00000   0.25000   1.00000
O2   0.83700   0.00000   0.08900   1.00000
O3   0.16400   0.48600   0.09400   1.00000