Mg(CO3)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in an octahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. In the second Mg site, Mg(2) is bonded in a distorted octahedral geometry to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(6) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(3), one O(4), and one O(5) atom. There are six inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one Mg(2) and one C(1) atom. In the second O site, O(1) is bonded in a linear geometry to one Mg(1) and one C(1) atom. In the third O site, O(2) is bonded in a linear geometry to one Mg(1) and one C(1) atom. In the fourth O site, O(3) is bonded in an L-shaped geometry to one Mg(2) and one C(2) atom. In the fifth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Mg(1) and one C(2) atom. In the sixth O site, O(5) is bonded in an L-shaped geometry to one Mg(2) and one C(2) atom.
Mg(CO3)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in an octahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. Both Mg(1)-O(1) bond lengths are 2.06 Å. Both Mg(1)-O(2) bond lengths are 2.15 Å. Both Mg(1)-O(4) bond lengths are 2.03 Å. In the second Mg site, Mg(2) is bonded in a distorted octahedral geometry to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. Both Mg(2)-O(3) bond lengths are 2.18 Å. Both Mg(2)-O(5) bond lengths are 2.13 Å. Both Mg(2)-O(6) bond lengths are 2.06 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(6) atom. The C(1)-O(1) bond length is 1.27 Å. The C(1)-O(2) bond length is 1.28 Å. The C(1)-O(6) bond length is 1.28 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(3), one O(4), and one O(5) atom. The C(2)-O(3) bond length is 1.29 Å. The C(2)-O(4) bond length is 1.26 Å. The C(2)-O(5) bond length is 1.29 Å. There are six inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one Mg(2) and one C(1) atom. In the second O site, O(1) is bonded in a linear geometry to one Mg(1) and one C(1) atom. In the third O site, O(2) is bonded in a linear geometry to one Mg(1) and one C(1) atom. In the fourth O site, O(3) is bonded in an L-shaped geometry to one Mg(2) and one C(2) atom. In the fifth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Mg(1) and one C(2) atom. In the sixth O site, O(5) is bonded in an L-shaped geometry to one Mg(2) and one C(2) atom.