Li2FeCPO7 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form distorted LiO4 trigonal pyramids that share corners with three equivalent Fe(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent Li(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 61-78°. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(4), one O(5), and one O(7) atom to form distorted LiO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent Li(1)O4 trigonal pyramids, and edges with two equivalent Fe(1)O6 octahedra. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form FeO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra, corners with three equivalent Li(1)O4 trigonal pyramids, and edges with two equivalent Li(2)O5 trigonal bipyramids. C(1) is bonded in a trigonal planar geometry to one O(1), one O(5), and one O(7) atom. P(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form PO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with two equivalent Li(2)O5 trigonal bipyramids, and corners with two equivalent Li(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 45-53°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Li(2), one Fe(1), and one C(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one C(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one Fe(1), and one C(1) atom.
Li2FeCPO7 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form distorted LiO4 trigonal pyramids that share corners with three equivalent Fe(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent Li(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 61-78°. The Li(1)-O(3) bond length is 2.03 Å. The Li(1)-O(5) bond length is 1.95 Å. The Li(1)-O(6) bond length is 2.27 Å. The Li(1)-O(7) bond length is 2.09 Å. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(4), one O(5), and one O(7) atom to form distorted LiO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent Li(1)O4 trigonal pyramids, and edges with two equivalent Fe(1)O6 octahedra. The Li(2)-O(1) bond length is 2.48 Å. The Li(2)-O(2) bond length is 2.01 Å. The Li(2)-O(4) bond length is 2.09 Å. The Li(2)-O(5) bond length is 1.97 Å. The Li(2)-O(7) bond length is 2.07 Å. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form FeO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra, corners with three equivalent Li(1)O4 trigonal pyramids, and edges with two equivalent Li(2)O5 trigonal bipyramids. The Fe(1)-O(1) bond length is 2.10 Å. The Fe(1)-O(2) bond length is 1.99 Å. The Fe(1)-O(3) bond length is 2.04 Å. The Fe(1)-O(4) bond length is 2.03 Å. The Fe(1)-O(6) bond length is 2.01 Å. The Fe(1)-O(7) bond length is 2.11 Å. C(1) is bonded in a trigonal planar geometry to one O(1), one O(5), and one O(7) atom. The C(1)-O(1) bond length is 1.30 Å. The C(1)-O(5) bond length is 1.27 Å. The C(1)-O(7) bond length is 1.34 Å. P(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form PO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with two equivalent Li(2)O5 trigonal bipyramids, and corners with two equivalent Li(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 45-53°. The P(1)-O(2) bond length is 1.56 Å. The P(1)-O(3) bond length is 1.55 Å. The P(1)-O(4) bond length is 1.54 Å. The P(1)-O(6) bond length is 1.56 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Li(2), one Fe(1), and one C(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(2), one Fe(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one C(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Fe(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Li(2), one Fe(1), and one C(1) atom.