FeCO3 crystallizes in the monoclinic Cc space group. Fe(1) is bonded to one C(1), one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted corner-sharing FeCO5 octahedra. The corner-sharing octahedral tilt angles range from 45-78°. C(1) is bonded in a distorted single-bond geometry to one Fe(1) and one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one O(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one O(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one C(1) atom.
FeCO3 crystallizes in the monoclinic Cc space group. Fe(1) is bonded to one C(1), one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted corner-sharing FeCO5 octahedra. The corner-sharing octahedral tilt angles range from 45-78°. The Fe(1)-C(1) bond length is 1.99 Å. The Fe(1)-O(3) bond length is 2.22 Å. There is one shorter (2.07 Å) and one longer (2.21 Å) Fe(1)-O(1) bond length. There is one shorter (2.08 Å) and one longer (2.12 Å) Fe(1)-O(2) bond length. C(1) is bonded in a distorted single-bond geometry to one Fe(1) and one O(3) atom. The C(1)-O(3) bond length is 1.17 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one O(2) atom. The O(1)-O(2) bond length is 1.47 Å. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Fe(1) and one O(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one C(1) atom.