BaFe2O4 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(1), two equivalent O(3), two equivalent O(4), two equivalent O(5), and three equivalent O(2) atoms. In the second Ba site, Ba(2) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(4), and two equivalent O(3) atoms to form corner-sharing FeO4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(2), one O(4), and two equivalent O(5) atoms to form corner-sharing FeO4 tetrahedra. There are five inequivalent O sites. In the first O site, O(4) is bonded in a 4-coordinate geometry to one Ba(1), one Ba(2), one Fe(1), and one Fe(2) atom. In the second O site, O(5) is bonded to one Ba(1), one Ba(2), and two equivalent Fe(2) atoms to form distorted corner-sharing OBa2Fe2 trigonal pyramids. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Ba(1), one Ba(2), and two equivalent Fe(1) atoms. In the fourth O site, O(2) is bonded in a distorted linear geometry to three equivalent Ba(1) and two equivalent Fe(2) atoms. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), one Ba(2), and two equivalent Fe(1) atoms.
BaFe2O4 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(1), two equivalent O(3), two equivalent O(4), two equivalent O(5), and three equivalent O(2) atoms. The Ba(1)-O(1) bond length is 2.76 Å. Both Ba(1)-O(3) bond lengths are 2.70 Å. Both Ba(1)-O(4) bond lengths are 3.14 Å. Both Ba(1)-O(5) bond lengths are 2.95 Å. There are a spread of Ba(1)-O(2) bond distances ranging from 2.92-3.21 Å. In the second Ba site, Ba(2) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. The Ba(2)-O(1) bond length is 2.94 Å. Both Ba(2)-O(3) bond lengths are 2.96 Å. Both Ba(2)-O(4) bond lengths are 2.72 Å. Both Ba(2)-O(5) bond lengths are 2.70 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(4), and two equivalent O(3) atoms to form corner-sharing FeO4 tetrahedra. The Fe(1)-O(1) bond length is 1.87 Å. The Fe(1)-O(4) bond length is 1.89 Å. Both Fe(1)-O(3) bond lengths are 1.89 Å. In the second Fe site, Fe(2) is bonded to one O(2), one O(4), and two equivalent O(5) atoms to form corner-sharing FeO4 tetrahedra. The Fe(2)-O(2) bond length is 1.88 Å. The Fe(2)-O(4) bond length is 1.89 Å. There is one shorter (1.88 Å) and one longer (1.89 Å) Fe(2)-O(5) bond length. There are five inequivalent O sites. In the first O site, O(4) is bonded in a 4-coordinate geometry to one Ba(1), one Ba(2), one Fe(1), and one Fe(2) atom. In the second O site, O(5) is bonded to one Ba(1), one Ba(2), and two equivalent Fe(2) atoms to form distorted corner-sharing OBa2Fe2 trigonal pyramids. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Ba(1), one Ba(2), and two equivalent Fe(1) atoms. In the fourth O site, O(2) is bonded in a distorted linear geometry to three equivalent Ba(1) and two equivalent Fe(2) atoms. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), one Ba(2), and two equivalent Fe(1) atoms.