Ba Ni O5 Yb2 Garcia-Matres E, Rodriguez-Carvajal J, Martinez J, Alonso J, Salinas-Sanchez A, Saez-Puche R Solid State Ionics 63 (1993) 915-921 Polymorphism in the oxides R2NaNiO5 (R= Tm, Yb, Lu) _cod_database_code 1006060 _database_code_amcsd 0015514 3.74482 5.70668 11.040 90 90 90 Immm atom x y z Ba1 .5 .5 0 Yb1 .5 0 .20323 Ni1 0 0 0 O1 0 .2393 .1504 O2 .5 0 0