Li2FeCu(PO4)2 is Hausmannite-derived structured and crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form LiO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Cu(1)O6 pentagonal pyramids, and edges with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-68°. In the second Li site, Li(2) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form LiO6 octahedra that share corners with four equivalent Cu(1)O6 pentagonal pyramids, corners with two equivalent P(2)O4 tetrahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent P(2)O4 tetrahedra. Fe(1) is bonded to one O(1), one O(5), two equivalent O(3), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with four equivalent Li(1)O6 octahedra, corners with four equivalent Cu(1)O6 pentagonal pyramids,  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, edges with two equivalent Li(2)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-68°. Cu(1) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(4) atoms to form distorted CuO6 pentagonal pyramids that share corners with four equivalent Li(2)O6 octahedra, corners with four equivalent Fe(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, edges with two equivalent Li(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-71°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra,  a cornercorner with one Cu(1)O6 pentagonal pyramid, edges with two equivalent Li(1)O6 octahedra, and  an edgeedge with one Cu(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 49-58°. In the second P site, P(2) is bonded to one O(5), one O(6), and two equivalent O(4) atoms to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with three equivalent Cu(1)O6 pentagonal pyramids,  an edgeedge with one Fe(1)O6 octahedra, and edges with two equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Li(1), one Fe(1), and one P(1) atom. In the second O site, O(2) is bonded to two equivalent Li(1), one Cu(1), and one P(1) atom to form distorted corner-sharing OLi2CuP tetrahedra. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Fe(1), one Cu(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Fe(1), one Cu(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li(2), one Fe(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to two equivalent Li(2), one Cu(1), and one P(2) atom.
Li2FeCu(PO4)2 is Hausmannite-derived structured and crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form LiO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Cu(1)O6 pentagonal pyramids, and edges with two equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-68°. Both Li(1)-O(1) bond lengths are 2.11 Å. Both Li(1)-O(2) bond lengths are 2.19 Å. Both Li(1)-O(3) bond lengths are 2.16 Å. In the second Li site, Li(2) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form LiO6 octahedra that share corners with four equivalent Cu(1)O6 pentagonal pyramids, corners with two equivalent P(2)O4 tetrahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent P(2)O4 tetrahedra. Both Li(2)-O(4) bond lengths are 2.16 Å. Both Li(2)-O(5) bond lengths are 2.15 Å. Both Li(2)-O(6) bond lengths are 2.15 Å. Fe(1) is bonded to one O(1), one O(5), two equivalent O(3), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with four equivalent Li(1)O6 octahedra, corners with four equivalent Cu(1)O6 pentagonal pyramids,  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, edges with two equivalent Li(2)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-68°. The Fe(1)-O(1) bond length is 2.07 Å. The Fe(1)-O(5) bond length is 2.19 Å. Both Fe(1)-O(3) bond lengths are 2.03 Å. Both Fe(1)-O(4) bond lengths are 2.17 Å. Cu(1) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(4) atoms to form distorted CuO6 pentagonal pyramids that share corners with four equivalent Li(2)O6 octahedra, corners with four equivalent Fe(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, edges with two equivalent Li(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-71°. The Cu(1)-O(2) bond length is 2.05 Å. The Cu(1)-O(6) bond length is 2.00 Å. Both Cu(1)-O(3) bond lengths are 2.40 Å. Both Cu(1)-O(4) bond lengths are 2.05 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with two equivalent Li(1)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra,  a cornercorner with one Cu(1)O6 pentagonal pyramid, edges with two equivalent Li(1)O6 octahedra, and  an edgeedge with one Cu(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 49-58°. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(2) bond length is 1.56 Å. Both P(1)-O(3) bond lengths are 1.56 Å. In the second P site, P(2) is bonded to one O(5), one O(6), and two equivalent O(4) atoms to form PO4 tetrahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with two equivalent Li(2)O6 octahedra, corners with three equivalent Cu(1)O6 pentagonal pyramids,  an edgeedge with one Fe(1)O6 octahedra, and edges with two equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles are 57°. The P(2)-O(5) bond length is 1.53 Å. The P(2)-O(6) bond length is 1.57 Å. Both P(2)-O(4) bond lengths are 1.57 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Li(1), one Fe(1), and one P(1) atom. In the second O site, O(2) is bonded to two equivalent Li(1), one Cu(1), and one P(1) atom to form distorted corner-sharing OLi2CuP tetrahedra. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Li(1), one Fe(1), one Cu(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), one Fe(1), one Cu(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li(2), one Fe(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to two equivalent Li(2), one Cu(1), and one P(2) atom.