Ba2FeO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Fe(1) is bonded in a distorted tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Ba(1), two equivalent Ba(2), and one Fe(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and one Fe(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and one Fe(1) atom.
Ba2FeO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. The Ba(1)-O(1) bond length is 2.69 Å. There is one shorter (2.89 Å) and one longer (3.06 Å) Ba(1)-O(2) bond length. There is one shorter (2.71 Å) and one longer (3.05 Å) Ba(1)-O(3) bond length. There is one shorter (2.74 Å) and one longer (2.89 Å) Ba(1)-O(4) bond length. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There is one shorter (2.79 Å) and one longer (3.01 Å) Ba(2)-O(1) bond length. There is one shorter (2.68 Å) and one longer (2.73 Å) Ba(2)-O(2) bond length. There is one shorter (2.74 Å) and one longer (2.85 Å) Ba(2)-O(3) bond length. There is one shorter (2.73 Å) and one longer (2.90 Å) Ba(2)-O(4) bond length. Fe(1) is bonded in a distorted tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Fe(1)-O(1) bond length is 1.77 Å. The Fe(1)-O(2) bond length is 1.77 Å. The Fe(1)-O(3) bond length is 1.78 Å. The Fe(1)-O(4) bond length is 1.80 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Ba(1), two equivalent Ba(2), and one Fe(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and one Fe(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a 1-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and one Fe(1) atom.