Ca2Eu(CuO3)2 crystallizes in the monoclinic Cc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(3), one O(6), two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms. Eu(1) is bonded in a 8-coordinate geometry to one O(4), one O(5), two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(3), one O(4), and one O(5) atom. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(2), one O(3), one O(4), and one O(6) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(2), two equivalent Eu(1), and one Cu(1) atom to form a mixture of distorted edge and corner-sharing OCa2Eu2Cu trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Ca(2), two equivalent Eu(1), and one Cu(2) atom to form a mixture of distorted edge and corner-sharing OCa2Eu2Cu trigonal bipyramids. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), one Cu(1), and one Cu(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent Ca(1), one Eu(1), one Cu(1), and one Cu(2) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Eu(1), and one Cu(1) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Ca(2), two equivalent Ca(1), two equivalent Eu(1), and one Cu(2) atom.
Ca2Eu(CuO3)2 crystallizes in the monoclinic Cc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. There is one shorter (2.34 Å) and one longer (2.75 Å) Ca(1)-O(3) bond length. There is one shorter (2.35 Å) and one longer (2.77 Å) Ca(1)-O(4) bond length. There is one shorter (2.36 Å) and one longer (2.69 Å) Ca(1)-O(5) bond length. There is one shorter (2.38 Å) and one longer (2.75 Å) Ca(1)-O(6) bond length. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(3), one O(6), two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms. The Ca(2)-O(3) bond length is 2.54 Å. The Ca(2)-O(6) bond length is 2.97 Å. There is one shorter (2.41 Å) and one longer (2.56 Å) Ca(2)-O(1) bond length. There is one shorter (2.41 Å) and one longer (2.52 Å) Ca(2)-O(2) bond length. There is one shorter (2.39 Å) and one longer (2.54 Å) Ca(2)-O(5) bond length. Eu(1) is bonded in a 8-coordinate geometry to one O(4), one O(5), two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms. The Eu(1)-O(4) bond length is 2.58 Å. The Eu(1)-O(5) bond length is 2.89 Å. There is one shorter (2.41 Å) and one longer (2.48 Å) Eu(1)-O(1) bond length. There is one shorter (2.42 Å) and one longer (2.53 Å) Eu(1)-O(2) bond length. There is one shorter (2.42 Å) and one longer (2.57 Å) Eu(1)-O(6) bond length. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(3), one O(4), and one O(5) atom. The Cu(1)-O(1) bond length is 1.89 Å. The Cu(1)-O(3) bond length is 1.90 Å. The Cu(1)-O(4) bond length is 1.92 Å. The Cu(1)-O(5) bond length is 1.88 Å. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(2), one O(3), one O(4), and one O(6) atom. The Cu(2)-O(2) bond length is 1.90 Å. The Cu(2)-O(3) bond length is 1.91 Å. The Cu(2)-O(4) bond length is 1.91 Å. The Cu(2)-O(6) bond length is 1.89 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(2), two equivalent Eu(1), and one Cu(1) atom to form a mixture of distorted edge and corner-sharing OCa2Eu2Cu trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Ca(2), two equivalent Eu(1), and one Cu(2) atom to form a mixture of distorted edge and corner-sharing OCa2Eu2Cu trigonal bipyramids. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), one Cu(1), and one Cu(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent Ca(1), one Eu(1), one Cu(1), and one Cu(2) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Eu(1), and one Cu(1) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Ca(2), two equivalent Ca(1), two equivalent Eu(1), and one Cu(2) atom.