LiFe2C2O7 crystallizes in the monoclinic C2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a T-shaped geometry to one O(1) and two equivalent O(3) atoms. In the second Li site, Li(2) is bonded to one O(10), one O(4), one O(6), and one O(9) atom to form distorted LiO4 trigonal pyramids that share corners with two equivalent Fe(1)O4 tetrahedra and corners with two equivalent Fe(2)O4 tetrahedra. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(4), one O(5), one O(7), and one O(9) atom to form FeO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra and corners with two equivalent Li(2)O4 trigonal pyramids. In the second Fe site, Fe(2) is bonded to one O(10), one O(3), one O(5), and one O(6) atom to form FeO4 tetrahedra that share  a cornercorner with one Fe(1)O4 tetrahedra and corners with two equivalent Li(2)O4 trigonal pyramids. In the third Fe site, Fe(3) is bonded to one O(1), one O(11), one O(2), and one O(8) atom to form corner-sharing FeO4 tetrahedra. There are three inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(3), one O(8), and one O(9) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(2), one O(4), and one O(6) atom. In the third C site, C(3) is bonded in a trigonal planar geometry to one O(10), one O(11), and one O(7) atom. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a T-shaped geometry to one Li(1) and two equivalent Fe(3) atoms. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Fe(3) and one C(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Li(1), one Fe(2), and one C(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one C(2) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Fe(1) and one Fe(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(2), one Fe(2), and one C(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Fe(1) and one C(3) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Fe(3) and one C(1) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one C(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Li(2), one Fe(2), and one C(3) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Fe(3) and one C(3) atom.
LiFe2C2O7 crystallizes in the monoclinic C2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a T-shaped geometry to one O(1) and two equivalent O(3) atoms. The Li(1)-O(1) bond length is 2.07 Å. Both Li(1)-O(3) bond lengths are 2.09 Å. In the second Li site, Li(2) is bonded to one O(10), one O(4), one O(6), and one O(9) atom to form distorted LiO4 trigonal pyramids that share corners with two equivalent Fe(1)O4 tetrahedra and corners with two equivalent Fe(2)O4 tetrahedra. The Li(2)-O(10) bond length is 2.22 Å. The Li(2)-O(4) bond length is 2.13 Å. The Li(2)-O(6) bond length is 2.18 Å. The Li(2)-O(9) bond length is 2.12 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(4), one O(5), one O(7), and one O(9) atom to form FeO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra and corners with two equivalent Li(2)O4 trigonal pyramids. The Fe(1)-O(4) bond length is 2.03 Å. The Fe(1)-O(5) bond length is 1.75 Å. The Fe(1)-O(7) bond length is 2.03 Å. The Fe(1)-O(9) bond length is 2.05 Å. In the second Fe site, Fe(2) is bonded to one O(10), one O(3), one O(5), and one O(6) atom to form FeO4 tetrahedra that share  a cornercorner with one Fe(1)O4 tetrahedra and corners with two equivalent Li(2)O4 trigonal pyramids. The Fe(2)-O(10) bond length is 2.04 Å. The Fe(2)-O(3) bond length is 2.05 Å. The Fe(2)-O(5) bond length is 1.92 Å. The Fe(2)-O(6) bond length is 2.07 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(11), one O(2), and one O(8) atom to form corner-sharing FeO4 tetrahedra. The Fe(3)-O(1) bond length is 1.85 Å. The Fe(3)-O(11) bond length is 1.99 Å. The Fe(3)-O(2) bond length is 2.01 Å. The Fe(3)-O(8) bond length is 1.99 Å. There are three inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(3), one O(8), and one O(9) atom. The C(1)-O(3) bond length is 1.30 Å. The C(1)-O(8) bond length is 1.29 Å. The C(1)-O(9) bond length is 1.30 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(2), one O(4), and one O(6) atom. The C(2)-O(2) bond length is 1.29 Å. The C(2)-O(4) bond length is 1.31 Å. The C(2)-O(6) bond length is 1.29 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one O(10), one O(11), and one O(7) atom. The C(3)-O(10) bond length is 1.30 Å. The C(3)-O(11) bond length is 1.29 Å. The C(3)-O(7) bond length is 1.30 Å. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a T-shaped geometry to one Li(1) and two equivalent Fe(3) atoms. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Fe(3) and one C(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Li(1), one Fe(2), and one C(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one C(2) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Fe(1) and one Fe(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(2), one Fe(2), and one C(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Fe(1) and one C(3) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Fe(3) and one C(1) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one C(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Li(2), one Fe(2), and one C(3) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Fe(3) and one C(3) atom.