data_1008382
_chemical_name_systematic          'Yttrium barium copper oxide (1/2/3/6.91)'
_chemical_formula_structural       'Y Ba2 Cu3 O6.91'
_chemical_formula_sum              'Ba2 Cu3 O6.91 Y'
_publ_section_title
;
A study of the Cu-O chains in the high T~c~ superconductor Y Ba~2~
Cu~3~ O~7~ by high resolution neutron powder diffraction
;
loop_
_publ_author_name
  'Francois, M'
  'Junod, A'
  'Yvon, K'
  'Hewat, A W'
  'Capponi, J J'
  'Strobel, P'
  'Marezio, M'
  'Fischer, P'
_journal_name_full                 'Solid State Communications'
_journal_coden_ASTM                SSCOA4
_journal_volume                    66
_journal_year                      1988
_journal_page_first                1117
_journal_page_last                 1125
_cell_length_a                     3.8091(1)
_cell_length_b                     3.8788(1)
_cell_length_c                     11.6369(3)
_cell_angle_alpha                  90
_cell_angle_beta                   90
_cell_angle_gamma                  90
_cell_volume                       171.9
_cell_formula_units_Z              1
_symmetry_space_group_name_H-M     'P m m m'
_symmetry_Int_Tables_number        47
_symmetry_cell_setting             orthorhombic
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '-x,-y,z'
  'x,-y,-z'
  '-x,y,-z'
  '-x,-y,-z'
  'x,y,-z'
  '-x,y,z'
  'x,-y,z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
  Ba2+   2.000
  Y3+    3.000
  Cu3+   3.000
  Cu2+   2.000
  O2-   -2.000
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_calc_flag
  Ba1   Ba2+   2 t 0.5 0.5 0.1845(2) 1.  0 d
  Y1    Y3+    1 h 0.5 0.5 0.5 1.  0 d
  Cu1   Cu3+   1 a 0. 0. 0. 1.  0 d
  Cu2   Cu2+   2 q 0. 0. 0.3552(1) 1.  0 d
  O1    O2-    2 q 0. 0. 0.1595(1) 1.  0 d
  O2    O2-    2 s 0.5 0. 0.3779(1) 1.  0 d
  O3    O2-    2 r 0. 0.5 0.3772(1) 1.  0 d
  O4    O2-    2 k 0.0219(19) 0.5 0. 0.455(5)  0 d
loop_
_atom_site_aniso_label
_atom_site_aniso_B_11
_atom_site_aniso_B_12
_atom_site_aniso_B_13
_atom_site_aniso_B_22
_atom_site_aniso_B_23
_atom_site_aniso_B_33
  Ba1   0.25(2) 0. 0. 0.25(2) 0. 0.25(2)
  Y1    0.25(2) 0. 0. 0.25(2) 0. 0.25(2)
  Cu1   0.28(2) 0. 0. 0.28(2) 0. 0.28(2)
  Cu2   0.18(1) 0. 0. 0.18(1) 0. 0.18(1)
  O1    0.42(2) 0. 0. 0.42(2) 0. 0.42(2)
  O2    0.37(2) 0. 0. 0.37(2) 0. 0.37(2)
  O3    0.32(2) 0. 0. 0.32(2) 0. 0.32(2)
  O4    0.35(4) 0. 0. 0.35(4) 0. 0.35(4)
_refine_ls_R_factor_all            0.0207