BaCa(CO3)2 crystallizes in the trigonal P321 space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(3), four equivalent O(1), and four equivalent O(2) atoms. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. There are three inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to three equivalent O(3) atoms. In the second C site, C(2) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. In the third C site, C(3) is bonded in a trigonal planar geometry to three equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to two equivalent Ba(1), one Ca(1), and one C(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Ba(1), one Ca(1), and one C(3) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ca(1), and one C(1) atom.
BaCa(CO3)2 crystallizes in the trigonal P321 space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(3), four equivalent O(1), and four equivalent O(2) atoms. Both Ba(1)-O(3) bond lengths are 2.82 Å. There are two shorter (2.87 Å) and two longer (2.89 Å) Ba(1)-O(1) bond lengths. There are two shorter (2.84 Å) and two longer (2.88 Å) Ba(1)-O(2) bond lengths. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Both Ca(1)-O(1) bond lengths are 2.40 Å. Both Ca(1)-O(2) bond lengths are 2.50 Å. There are two shorter (2.58 Å) and two longer (2.62 Å) Ca(1)-O(3) bond lengths. There are three inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to three equivalent O(3) atoms. All C(1)-O(3) bond lengths are 1.30 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. All C(2)-O(1) bond lengths are 1.30 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to three equivalent O(2) atoms. All C(3)-O(2) bond lengths are 1.30 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to two equivalent Ba(1), one Ca(1), and one C(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Ba(1), one Ca(1), and one C(3) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ca(1), and one C(1) atom.