Ba Ni O5 Yb2 Salinas-Sanchez A, Saez-Puche R, Rodriguez-Carvajal J, Martinez J Solid State Communications 78 (1991) 481-488 Structural characterization of R2BaNiO5 (R=Tm and Yb): polymorphism for R=Tm _cod_database_code 1006038 _database_code_amcsd 0015485 12.1583 5.64232 6.9545 90 90 90 Pnma atom x y z Ba1 .9038 .25 .9250 Yb1 .2915 .25 .1241 Yb2 .0744 .25 .3994 Ni1 .6560 .25 .6955 O1 .4359 -.0030 .1699 O2 .2250 .5001 .3642 O3 .1037 .25 .0791