BaMg(CO3)2 crystallizes in the trigonal R-3c space group. Ba(1) is bonded to twelve equivalent O(1) atoms to form BaO12 cuboctahedra that share edges with six equivalent Ba(1)O12 cuboctahedra and edges with six equivalent Mg(1)O6 octahedra. Mg(1) is bonded to six equivalent O(1) atoms to form MgO6 octahedra that share edges with six equivalent Ba(1)O12 cuboctahedra. C(1) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. O(1) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Mg(1), and one C(1) atom.
BaMg(CO3)2 crystallizes in the trigonal R-3c space group. Ba(1) is bonded to twelve equivalent O(1) atoms to form BaO12 cuboctahedra that share edges with six equivalent Ba(1)O12 cuboctahedra and edges with six equivalent Mg(1)O6 octahedra. There are six shorter (2.85 Å) and six longer (3.11 Å) Ba(1)-O(1) bond lengths. Mg(1) is bonded to six equivalent O(1) atoms to form MgO6 octahedra that share edges with six equivalent Ba(1)O12 cuboctahedra. All Mg(1)-O(1) bond lengths are 2.09 Å. C(1) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. All C(1)-O(1) bond lengths are 1.30 Å. O(1) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Mg(1), and one C(1) atom.