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 1008400 _database_code_amcsd 0016309 3.8097 3.8788 11.6397 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 .32 .32 .32 0 0 0 Y1 .5 .5 .5 .26 .26 .26 0 0 0 Cu1 0 0 0 .28 .28 .28 0 0 0 Cu2 0 0 .3550 .23 .23 .23 0 0 0 O1 0 0 .1594 .43 .43 .43 0 0 0 O2 .5 0 .3781 .38 .38 .38 0 0 0 O3 0 .5 .3775 .36 .36 .36 0 0 0 O4 0 .5 0 .91 .92 .18 .43 0 0 0