data_global _amcsd_formula_title 'Ba2 Cu3 O6.91 Y' loop_ _publ_author_name 'Francois M' 'Junod A' 'Yvon K' 'Hewat A' 'Capponi J' 'Strobel P' 'Marezio M' 'Fischer P' _journal_name_full 'Solid State Communications' _journal_volume 66 _journal_year 1988 _journal_page_first 1117 _journal_page_last 1125 _publ_section_title ; A study of the Cu-O chains in the high Tc superconductor Y Ba2 Cu3 O7 by high resolution neutron powder diffraction _cod_database_code 1008413 ; _database_code_amcsd 0016322 _chemical_formula_sum 'Ba2 Y Cu3 O6.91' _cell_length_a 3.8177 _cell_length_b 3.8836 _cell_length_c 11.6827 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 173.213 _exptl_crystal_density_diffrn 6.373 _symmetry_space_group_name_H-M 'P m m m' loop_ _space_group_symop_operation_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_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy Ba1 0.50000 0.50000 0.18440 1.00000 Y1 0.50000 0.50000 0.50000 1.00000 Cu1 0.00000 0.00000 0.00000 1.00000 Cu2 0.00000 0.00000 0.35520 1.00000 O1 0.00000 0.00000 0.15880 1.00000 O2 0.50000 0.00000 0.37790 1.00000 O3 0.00000 0.50000 0.37800 1.00000 O4 0.00000 0.50000 0.00000 0.91000 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 Ba1 0.47256 0.48901 4.42524 0.00000 0.00000 0.00000 Y1 0.36180 0.37440 3.38807 0.00000 0.00000 0.00000 Cu1 0.37657 0.38968 3.52636 0.00000 0.00000 0.00000 Cu2 0.38395 0.39732 3.59551 0.00000 0.00000 0.00000 O1 0.55378 0.57306 5.18583 0.00000 0.00000 0.00000 O2 0.45779 0.47373 4.28695 0.00000 0.00000 0.00000 O3 0.47256 0.48901 4.42524 0.00000 0.00000 0.00000 O4 1.77209 0.12989 5.39326 0.00000 0.00000 0.00000