Li3FeCO3PO4 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(4), and one O(5) atom. In the second Li site, Li(2) is bonded to one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form distorted LiO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra and edges with two equivalent Fe(1)O5 trigonal bipyramids. In the third Li site, Li(3) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. Fe(1) is bonded to one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form distorted FeO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra 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(2), and one O(3) atom. P(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Li(2)O5 trigonal bipyramids and corners with three equivalent Fe(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(6) is bonded to one Li(2), one Li(3), one Fe(1), and one P(1) atom to form distorted OLi2FeP trigonal pyramids that share corners with two equivalent O(2)Li2FeC tetrahedra and corners with four equivalent O(7)Li2FeP tetrahedra. In the second O site, O(7) is bonded to one Li(2), one Li(3), one Fe(1), and one P(1) atom to form distorted OLi2FeP tetrahedra that share corners with four equivalent O(6)Li2FeP trigonal pyramids and  an edgeedge with one O(2)Li2FeC tetrahedra. In the third O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Li(1), one Li(3), and one C(1) atom. In the fourth O site, O(2) is bonded to one Li(1), one Li(2), one Fe(1), and one C(1) atom to form a mixture of distorted corner and edge-sharing OLi2FeC tetrahedra. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Li(2), one Li(3), one Fe(1), and one C(1) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Li(3), and one P(1) atom. In the seventh O site, O(5) is bonded in a 4-coordinate geometry to one Li(1), one Li(3), one Fe(1), and one P(1) atom.
Li3FeCO3PO4 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(4), and one O(5) atom. The Li(1)-O(1) bond length is 1.92 Å. The Li(1)-O(2) bond length is 1.99 Å. The Li(1)-O(4) bond length is 2.19 Å. The Li(1)-O(5) bond length is 2.23 Å. In the second Li site, Li(2) is bonded to one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form distorted LiO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra and edges with two equivalent Fe(1)O5 trigonal bipyramids. The Li(2)-O(2) bond length is 2.23 Å. The Li(2)-O(3) bond length is 2.44 Å. The Li(2)-O(4) bond length is 2.04 Å. The Li(2)-O(6) bond length is 2.07 Å. The Li(2)-O(7) bond length is 2.12 Å. In the third Li site, Li(3) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. The Li(3)-O(1) bond length is 2.47 Å. The Li(3)-O(3) bond length is 2.27 Å. The Li(3)-O(4) bond length is 2.01 Å. The Li(3)-O(5) bond length is 2.06 Å. The Li(3)-O(6) bond length is 2.11 Å. The Li(3)-O(7) bond length is 2.07 Å. Fe(1) is bonded to one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form distorted FeO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra and edges with two equivalent Li(2)O5 trigonal bipyramids. The Fe(1)-O(2) bond length is 2.14 Å. The Fe(1)-O(3) bond length is 2.12 Å. The Fe(1)-O(5) bond length is 2.10 Å. The Fe(1)-O(6) bond length is 2.11 Å. The Fe(1)-O(7) bond length is 2.24 Å. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The C(1)-O(1) bond length is 1.28 Å. The C(1)-O(2) bond length is 1.32 Å. The C(1)-O(3) bond length is 1.30 Å. P(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Li(2)O5 trigonal bipyramids and corners with three equivalent Fe(1)O5 trigonal bipyramids. The P(1)-O(4) bond length is 1.55 Å. The P(1)-O(5) bond length is 1.57 Å. The P(1)-O(6) bond length is 1.55 Å. The P(1)-O(7) bond length is 1.56 Å. There are seven inequivalent O sites. In the first O site, O(6) is bonded to one Li(2), one Li(3), one Fe(1), and one P(1) atom to form distorted OLi2FeP trigonal pyramids that share corners with two equivalent O(2)Li2FeC tetrahedra and corners with four equivalent O(7)Li2FeP tetrahedra. In the second O site, O(7) is bonded to one Li(2), one Li(3), one Fe(1), and one P(1) atom to form distorted OLi2FeP tetrahedra that share corners with four equivalent O(6)Li2FeP trigonal pyramids and  an edgeedge with one O(2)Li2FeC tetrahedra. In the third O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Li(1), one Li(3), and one C(1) atom. In the fourth O site, O(2) is bonded to one Li(1), one Li(2), one Fe(1), and one C(1) atom to form a mixture of distorted corner and edge-sharing OLi2FeC tetrahedra. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Li(2), one Li(3), one Fe(1), and one C(1) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Li(3), and one P(1) atom. In the seventh O site, O(5) is bonded in a 4-coordinate geometry to one Li(1), one Li(3), one Fe(1), and one P(1) atom.