Eu2CoO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) 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. In the second Eu site, Eu(2) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Co(1) is bonded in a 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 5-coordinate geometry to two equivalent Eu(1), two equivalent Eu(2), and one Co(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Eu(1), two equivalent Eu(2), and one Co(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to two equivalent Eu(1), two equivalent Eu(2), and one Co(1) atom. In the fourth O site, O(4) is bonded in a distorted see-saw-like geometry to one Eu(2), two equivalent Eu(1), and one Co(1) atom.
Eu2CoO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) 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 (2.45 Å) and one longer (2.83 Å) Eu(1)-O(1) bond length. There is one shorter (2.42 Å) and one longer (2.49 Å) Eu(1)-O(2) bond length. There is one shorter (2.46 Å) and one longer (2.86 Å) Eu(1)-O(3) bond length. There is one shorter (2.51 Å) and one longer (2.57 Å) Eu(1)-O(4) bond length. In the second Eu site, Eu(2) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. The Eu(2)-O(4) bond length is 2.33 Å. There is one shorter (2.43 Å) and one longer (2.58 Å) Eu(2)-O(1) bond length. There is one shorter (2.54 Å) and one longer (2.96 Å) Eu(2)-O(2) bond length. There is one shorter (2.40 Å) and one longer (2.66 Å) Eu(2)-O(3) bond length. Co(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Co(1)-O(1) bond length is 1.87 Å. The Co(1)-O(2) bond length is 1.86 Å. The Co(1)-O(3) bond length is 1.89 Å. The Co(1)-O(4) bond length is 1.82 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Eu(1), two equivalent Eu(2), and one Co(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Eu(1), two equivalent Eu(2), and one Co(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to two equivalent Eu(1), two equivalent Eu(2), and one Co(1) atom. In the fourth O site, O(4) is bonded in a distorted see-saw-like geometry to one Eu(2), two equivalent Eu(1), and one Co(1) atom.