Ca2Co2O5 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), two equivalent O(2), and two equivalent O(4) atoms. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) atom. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing CoO5 square pyramids. In the second Co site, Co(2) is bonded to one O(1), two equivalent O(2), and two equivalent O(5) atoms to form corner-sharing CoO5 square pyramids. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Co(1), and one Co(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), and two equivalent Co(2) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), and two equivalent Co(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), and two equivalent Co(1) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), and two equivalent Co(2) atoms.
Ca2Co2O5 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), two equivalent O(2), and two equivalent O(4) atoms. The Ca(1)-O(1) bond length is 2.41 Å. The Ca(1)-O(3) bond length is 2.33 Å. The Ca(1)-O(5) bond length is 2.35 Å. There is one shorter (2.51 Å) and one longer (2.80 Å) Ca(1)-O(2) bond length. There is one shorter (2.46 Å) and one longer (2.82 Å) Ca(1)-O(4) bond length. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) atom. The Ca(2)-O(1) bond length is 2.26 Å. The Ca(2)-O(2) bond length is 2.33 Å. The Ca(2)-O(3) bond length is 2.39 Å. The Ca(2)-O(4) bond length is 2.30 Å. The Ca(2)-O(5) bond length is 2.38 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing CoO5 square pyramids. The Co(1)-O(1) bond length is 1.84 Å. There is one shorter (1.88 Å) and one longer (2.02 Å) Co(1)-O(3) bond length. There is one shorter (1.90 Å) and one longer (1.97 Å) Co(1)-O(4) bond length. In the second Co site, Co(2) is bonded to one O(1), two equivalent O(2), and two equivalent O(5) atoms to form corner-sharing CoO5 square pyramids. The Co(2)-O(1) bond length is 1.95 Å. There is one shorter (1.91 Å) and one longer (1.95 Å) Co(2)-O(2) bond length. There is one shorter (1.87 Å) and one longer (2.00 Å) Co(2)-O(5) bond length. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Co(1), and one Co(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), and two equivalent Co(2) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), and two equivalent Co(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), and two equivalent Co(1) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), and two equivalent Co(2) atoms.