Li3FeCO3PO4 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(2), one O(5), and two equivalent O(6) atoms. In the second Li site, Li(2) is bonded to one O(1), one O(3), one O(4), one O(5), and one O(6) atom to form LiO5 trigonal bipyramids that share corners with two equivalent Fe(1)O6 octahedra, corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and edges with two equivalent Li(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 66-88°. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(6) atoms to form distorted FeO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra, corners with four equivalent Li(2)O5 trigonal bipyramids, and edges with two equivalent Li(2)O5 trigonal bipyramids. C(1) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(5) atom. P(1) is bonded to one O(1), one O(4), and two equivalent O(6) atoms to form PO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra and corners with six equivalent Li(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 42-62°. There are six inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(2), one Fe(1), and one P(1) atom to form distorted OLi2FeP trigonal pyramids that share corners with two equivalent O(5)Li3C tetrahedra, corners with four equivalent O(4)Li2FeP tetrahedra,  a cornercorner with one O(3)Li2FeC trigonal pyramid, corners with two equivalent O(6)Li2FeP trigonal pyramids,  an edgeedge with one O(3)Li2FeC trigonal pyramid, and edges with two equivalent O(6)Li2FeP trigonal pyramids. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Fe(1), and one C(1) atom. In the third O site, O(3) is bonded to two equivalent Li(2), one Fe(1), and one C(1) atom to form distorted OLi2FeC trigonal pyramids that share corners with three equivalent O(4)Li2FeP tetrahedra, corners with three equivalent O(5)Li3C tetrahedra,  a cornercorner with one O(1)Li2FeP trigonal pyramid, corners with four equivalent O(6)Li2FeP trigonal pyramids, and  an edgeedge with one O(1)Li2FeP trigonal pyramid. In the fourth O site, O(4) is bonded to two equivalent Li(2), one Fe(1), and one P(1) atom to form distorted OLi2FeP tetrahedra that share corners with three equivalent O(3)Li2FeC trigonal pyramids, corners with four equivalent O(1)Li2FeP trigonal pyramids, corners with six equivalent O(6)Li2FeP trigonal pyramids, and  an edgeedge with one O(5)Li3C tetrahedra. In the fifth O site, O(5) is bonded to one Li(1), two equivalent Li(2), and one C(1) atom to form OLi3C tetrahedra that share corners with two equivalent O(1)Li2FeP trigonal pyramids, corners with three equivalent O(3)Li2FeC trigonal pyramids, corners with four equivalent O(6)Li2FeP trigonal pyramids, and  an edgeedge with one O(4)Li2FeP tetrahedra. In the sixth O site, O(6) is bonded to one Li(1), one Li(2), one Fe(1), and one P(1) atom to form distorted OLi2FeP trigonal pyramids that share corners with two equivalent O(5)Li3C tetrahedra, corners with three equivalent O(4)Li2FeP tetrahedra,  a cornercorner with one O(1)Li2FeP trigonal pyramid,  a cornercorner with one O(6)Li2FeP trigonal pyramid, corners with two equivalent O(3)Li2FeC trigonal pyramids,  an edgeedge with one O(1)Li2FeP trigonal pyramid, and  an edgeedge with one O(6)Li2FeP trigonal pyramid.
Li3FeCO3PO4 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(2), one O(5), and two equivalent O(6) atoms. The Li(1)-O(2) bond length is 1.91 Å. The Li(1)-O(5) bond length is 2.01 Å. Both Li(1)-O(6) bond lengths are 2.14 Å. In the second Li site, Li(2) is bonded to one O(1), one O(3), one O(4), one O(5), and one O(6) atom to form LiO5 trigonal bipyramids that share corners with two equivalent Fe(1)O6 octahedra, corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and edges with two equivalent Li(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 66-88°. The Li(2)-O(1) bond length is 2.18 Å. The Li(2)-O(3) bond length is 2.20 Å. The Li(2)-O(4) bond length is 2.20 Å. The Li(2)-O(5) bond length is 2.14 Å. The Li(2)-O(6) bond length is 2.18 Å. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(6) atoms to form distorted FeO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra, corners with four equivalent Li(2)O5 trigonal bipyramids, and edges with two equivalent Li(2)O5 trigonal bipyramids. The Fe(1)-O(1) bond length is 2.18 Å. The Fe(1)-O(2) bond length is 2.30 Å. The Fe(1)-O(3) bond length is 2.24 Å. The Fe(1)-O(4) bond length is 2.19 Å. Both Fe(1)-O(6) bond lengths are 2.04 Å. C(1) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(5) atom. The C(1)-O(2) bond length is 1.29 Å. The C(1)-O(3) bond length is 1.31 Å. The C(1)-O(5) bond length is 1.30 Å. P(1) is bonded to one O(1), one O(4), and two equivalent O(6) atoms to form PO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra and corners with six equivalent Li(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 42-62°. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(4) bond length is 1.56 Å. Both P(1)-O(6) bond lengths are 1.56 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(2), one Fe(1), and one P(1) atom to form distorted OLi2FeP trigonal pyramids that share corners with two equivalent O(5)Li3C tetrahedra, corners with four equivalent O(4)Li2FeP tetrahedra,  a cornercorner with one O(3)Li2FeC trigonal pyramid, corners with two equivalent O(6)Li2FeP trigonal pyramids,  an edgeedge with one O(3)Li2FeC trigonal pyramid, and edges with two equivalent O(6)Li2FeP trigonal pyramids. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Li(1), one Fe(1), and one C(1) atom. In the third O site, O(3) is bonded to two equivalent Li(2), one Fe(1), and one C(1) atom to form distorted OLi2FeC trigonal pyramids that share corners with three equivalent O(4)Li2FeP tetrahedra, corners with three equivalent O(5)Li3C tetrahedra,  a cornercorner with one O(1)Li2FeP trigonal pyramid, corners with four equivalent O(6)Li2FeP trigonal pyramids, and  an edgeedge with one O(1)Li2FeP trigonal pyramid. In the fourth O site, O(4) is bonded to two equivalent Li(2), one Fe(1), and one P(1) atom to form distorted OLi2FeP tetrahedra that share corners with three equivalent O(3)Li2FeC trigonal pyramids, corners with four equivalent O(1)Li2FeP trigonal pyramids, corners with six equivalent O(6)Li2FeP trigonal pyramids, and  an edgeedge with one O(5)Li3C tetrahedra. In the fifth O site, O(5) is bonded to one Li(1), two equivalent Li(2), and one C(1) atom to form OLi3C tetrahedra that share corners with two equivalent O(1)Li2FeP trigonal pyramids, corners with three equivalent O(3)Li2FeC trigonal pyramids, corners with four equivalent O(6)Li2FeP trigonal pyramids, and  an edgeedge with one O(4)Li2FeP tetrahedra. In the sixth O site, O(6) is bonded to one Li(1), one Li(2), one Fe(1), and one P(1) atom to form distorted OLi2FeP trigonal pyramids that share corners with two equivalent O(5)Li3C tetrahedra, corners with three equivalent O(4)Li2FeP tetrahedra,  a cornercorner with one O(1)Li2FeP trigonal pyramid,  a cornercorner with one O(6)Li2FeP trigonal pyramid, corners with two equivalent O(3)Li2FeC trigonal pyramids,  an edgeedge with one O(1)Li2FeP trigonal pyramid, and  an edgeedge with one O(6)Li2FeP trigonal pyramid.