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 1008385 _database_code_amcsd 0016294 3.8097 3.8788 11.6409 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 .26 .26 .26 0 0 0 Y1 .5 .5 .5 .28 .28 .28 0 0 0 Cu1 0 0 0 .30 .30 .30 0 0 0 Cu2 0 0 .3551 .22 .22 .22 0 0 0 O1 0 0 .1594 .51 .51 .51 0 0 0 O2 .5 0 .3781 .40 .40 .40 0 0 0 O3 0 .5 .3774 .36 .36 .36 0 0 0 O4 .0225 .5 0 .455 .35 .35 .35 0 0 0