Ba2 Ca0.09 Cu2.91 Fe0.09 O7.01 Y0.91 Suard E, Caignaert V, Maignan A, Raveau B Physica C 182 (1991) 219-227 The important role of pyramidal copper layers of the 123-structure in superconductivity. The oxides Ba2Y1-xCaxCu3-xFexO7 and Ba2Y1-xCaxCu3-xFexO6 _cod_database_code 1001490 _database_code_amcsd 0015029 3.8602 3.8602 11.6646 90 90 90 P4/mmm atom x y z occ Y1 .5 .5 .5 .91 Ca1 .5 .5 .5 .09 Ba1 .5 .5 .1857 Cu1 0 0 0 .91 Fe1 0 0 0 .09 Cu2 0 0 .3566 O1 0 .5 .3771 O2 0 0 .1579 O3 0 .5 0 .505