Ni3 O9 Sr4 Abraham F, Minaud S, Renard C Journal of Materials Chemistry 4 (1994) 1763-1764 Preliminary crystal structure of mixed-valency Sr4 Ni3 O9, the actual formula of the so-called Sr5 Ni4 O11 _cod_database_code 1004109 _database_code_amcsd 0013072 9.477 9.477 7.825 90 90 120 P321 atom x y z occ Sr1 .0233 .6918 .2476 Sr2 .3276 0 .5 Sr3 .3603 0 0 Ni1 1/3 2/3 .1086 Ni2 1/3 2/3 .4217 Ni3 0 0 .3383 Ni4 2/3 1/3 .237 .58 Ni5 0 0 0 .655 Ni6 .610 .273 .241 .14 Ni7 .924 0 0 .115 O1 .819 .5 .038 O2 .158 .007 .190 O3 .172 .519 .263 O4 .671 .177 .445 O5 .846 0 .5