Ba Ni O5 Tm2 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 1006037 _database_code_amcsd 0015484 3.75128 5.7214 11.2456 90 90 90 Immm atom x y z Ba1 0 .5 0 Tm1 0 0 .2032 Ni1 .5 0 0 O1 .5 .2403 .1500 O2 0 0 0