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 1008390 _database_code_amcsd 0016299 3.8121 3.8798 11.6542 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 .1843 .43 .43 .43 0 0 0 Y1 .5 .5 .5 .33 .33 .33 0 0 0 Cu1 0 0 0 .37 .37 .37 0 0 0 Cu2 0 0 .3552 .32 .32 .32 0 0 0 O1 0 0 .1591 .56 .56 .56 0 0 0 O2 .5 0 .3779 .43 .43 .43 0 0 0 O3 0 .5 .3778 .44 .44 .44 0 0 0 O4 .0278 .5 0 .455 .38 .38 .38 0 0 0