BaCa(CO3)2 crystallizes in the monoclinic P2_1/m space group. Ba(1) is bonded in a 11-coordinate geometry to two equivalent O(1), two equivalent O(4), three equivalent O(2), and four equivalent O(3) atoms. Ca(1) is bonded to one O(4), two equivalent O(3), and four equivalent O(1) atoms to form distorted edge-sharing CaO7 pentagonal bipyramids. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(4) and two equivalent O(1) atoms. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(2) and two equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Ca(1), and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to three equivalent Ba(1) and one C(2) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to two equivalent Ba(1), one Ca(1), and one C(2) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Ca(1), and one C(1) atom.
BaCa(CO3)2 crystallizes in the monoclinic P2_1/m space group. Ba(1) is bonded in a 11-coordinate geometry to two equivalent O(1), two equivalent O(4), three equivalent O(2), and four equivalent O(3) atoms. Both Ba(1)-O(1) bond lengths are 2.89 Å. Both Ba(1)-O(4) bond lengths are 3.19 Å. There is one shorter (2.76 Å) and two longer (2.95 Å) Ba(1)-O(2) bond lengths. There are two shorter (2.89 Å) and two longer (2.95 Å) Ba(1)-O(3) bond lengths. Ca(1) is bonded to one O(4), two equivalent O(3), and four equivalent O(1) atoms to form distorted edge-sharing CaO7 pentagonal bipyramids. The Ca(1)-O(4) bond length is 2.40 Å. Both Ca(1)-O(3) bond lengths are 2.34 Å. There are two shorter (2.38 Å) and two longer (2.55 Å) Ca(1)-O(1) bond lengths. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(4) and two equivalent O(1) atoms. The C(1)-O(4) bond length is 1.28 Å. Both C(1)-O(1) bond lengths are 1.31 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(2) and two equivalent O(3) atoms. The C(2)-O(2) bond length is 1.29 Å. Both C(2)-O(3) bond lengths are 1.31 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Ca(1), and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to three equivalent Ba(1) and one C(2) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to two equivalent Ba(1), one Ca(1), and one C(2) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Ca(1), and one C(1) atom.