Ba2 Cu3 O6.91 Y Francois M, Junod A, Yvon K, Hewat A, Capponi J, Strobel P, Marezio M, Fischer P Solid State Communications 66 (1988) 1117-1125 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 1008393 _database_code_amcsd 0016302 3.8143 3.8812 11.6662 90 90 90 Pmmm atom x y z occ B(1,1) B(2,2) B(3,3) B(1,2) B(1,3) B(2,3) Ba1 .5 .5 .1841 .51 .51 .51 0 0 0 Y1 .5 .5 .5 .38 .38 .38 0 0 0 Cu1 0 0 0 .44 .44 .44 0 0 0 Cu2 0 0 .3552 .40 .40 .40 0 0 0 O1 0 0 .1590 .64 .64 .64 0 0 0 O2 .5 0 .3780 .52 .52 .52 0 0 0 O3 0 .5 .3778 .53 .53 .53 0 0 0 O4 .0313 .5 0 .455 .48 .48 .48 0 0 0