data_global
_amcsd_formula_title 'Ba2CuSi2O7'
loop_
_publ_author_name
'Du J M'
'Zeng H Y'
'Song L J'
'Dong Z C'
'Ma H W'
'Guo G C'
'Huang J S'
_journal_name_full 'Jiegou Huaxue'
_journal_volume 22 
_journal_year 2003
_journal_page_first 33
_journal_page_last 36
_publ_section_title
;
 Synthesis and structure of a new polymorph Ba2CuSi2O7
 Note: known as beta-Ba2CuSi2O7
;
_database_code_amcsd 0018759
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Ba2 Cu Si2 O7'
_cell_length_a 8.284
_cell_length_b 8.284
_cell_length_c 5.313
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 364.603
_exptl_crystal_density_diffrn      4.612
_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
_atom_site_U_iso_or_equiv
Ba   0.33311   0.16689   0.50910   0.00934
Cu   0.00000   0.00000   0.00000   0.01050
Si   0.13500   0.36500   0.97340   0.00760
O1   0.00000   0.50000   0.87000   0.01100
O2   0.13560   0.36438   0.27700   0.01100
O3   0.07900   0.19650   0.84000   0.01300