Li4Cr7(PO4)6 crystallizes in the monoclinic Cm space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted T-shaped geometry to one O(2) and two equivalent O(10) atoms. In the second Li site, Li(2) is bonded in a distorted T-shaped geometry to one O(5), one O(7), and one O(9) atom. In the third Li site, Li(3) is bonded in an L-shaped geometry to two equivalent O(4) atoms. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 5-coordinate geometry to one O(12), one O(13), one O(14), one O(3), and one O(8) atom. In the second Cr site, Cr(2) is bonded to one O(1), one O(13), one O(5), one O(6), and one O(9) atom to form distorted CrO5 square pyramids that share corners with two equivalent Cr(4)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-65°. In the third Cr site, Cr(3) is bonded to one O(11), two equivalent O(4), and two equivalent O(8) atoms to form CrO5 square pyramids that share corners with two equivalent Cr(4)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 68°. In the fourth Cr site, Cr(4) is bonded to one O(1), one O(10), one O(12), one O(3), one O(4), and one O(5) atom to form distorted CrO6 octahedra that share  a cornercorner with one Cr(3)O5 square pyramid, corners with two equivalent Cr(2)O5 square pyramids,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one P(1)O4 tetrahedra. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(14), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(4)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one Cr(3)O5 square pyramid, and  an edgeedge with one Cr(4)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the second P site, P(2) is bonded to one O(2), one O(6), and two equivalent O(1) atoms to form PO4 tetrahedra that share corners with two equivalent Cr(4)O6 octahedra and edges with two equivalent Cr(2)O5 square pyramids. The corner-sharing octahedral tilt angles are 53°. In the third P site, P(3) is bonded to one O(11), one O(7), and two equivalent O(13) atoms to form PO4 tetrahedra that share  a cornercorner with one Cr(3)O5 square pyramid and corners with two equivalent Cr(2)O5 square pyramids. In the fourth P site, P(4) is bonded to one O(10), one O(12), one O(8), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Cr(4)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid, and  a cornercorner with one Cr(3)O5 square pyramid. The corner-sharing octahedral tilt angles range from 43-52°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Cr(2), one Cr(4), and one P(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Li(1) and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Cr(1), one Cr(4), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(3), one Cr(3), one Cr(4), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted tetrahedral geometry to one Li(2), one Cr(2), one Cr(4), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Cr(2) and one P(2) atom. In the seventh O site, O(7) is bonded in a trigonal non-coplanar geometry to two equivalent Li(2) and one P(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Cr(1), one Cr(3), and one P(4) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Li(2), one Cr(2), and one P(4) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Li(1), one Cr(4), and one P(4) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one Cr(3) and one P(3) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Cr(1), one Cr(4), and one P(4) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(2), and one P(3) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom.
Li4Cr7(PO4)6 crystallizes in the monoclinic Cm space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted T-shaped geometry to one O(2) and two equivalent O(10) atoms. The Li(1)-O(2) bond length is 1.89 Å. Both Li(1)-O(10) bond lengths are 2.13 Å. In the second Li site, Li(2) is bonded in a distorted T-shaped geometry to one O(5), one O(7), and one O(9) atom. The Li(2)-O(5) bond length is 2.14 Å. The Li(2)-O(7) bond length is 2.00 Å. The Li(2)-O(9) bond length is 1.91 Å. In the third Li site, Li(3) is bonded in an L-shaped geometry to two equivalent O(4) atoms. Both Li(3)-O(4) bond lengths are 1.99 Å. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 5-coordinate geometry to one O(12), one O(13), one O(14), one O(3), and one O(8) atom. The Cr(1)-O(12) bond length is 2.28 Å. The Cr(1)-O(13) bond length is 2.34 Å. The Cr(1)-O(14) bond length is 2.01 Å. The Cr(1)-O(3) bond length is 2.05 Å. The Cr(1)-O(8) bond length is 2.20 Å. In the second Cr site, Cr(2) is bonded to one O(1), one O(13), one O(5), one O(6), and one O(9) atom to form distorted CrO5 square pyramids that share corners with two equivalent Cr(4)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-65°. The Cr(2)-O(1) bond length is 2.14 Å. The Cr(2)-O(13) bond length is 2.03 Å. The Cr(2)-O(5) bond length is 2.13 Å. The Cr(2)-O(6) bond length is 2.14 Å. The Cr(2)-O(9) bond length is 2.46 Å. In the third Cr site, Cr(3) is bonded to one O(11), two equivalent O(4), and two equivalent O(8) atoms to form CrO5 square pyramids that share corners with two equivalent Cr(4)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 68°. The Cr(3)-O(11) bond length is 2.19 Å. Both Cr(3)-O(4) bond lengths are 2.08 Å. Both Cr(3)-O(8) bond lengths are 2.08 Å. In the fourth Cr site, Cr(4) is bonded to one O(1), one O(10), one O(12), one O(3), one O(4), and one O(5) atom to form distorted CrO6 octahedra that share  a cornercorner with one Cr(3)O5 square pyramid, corners with two equivalent Cr(2)O5 square pyramids,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one P(1)O4 tetrahedra. The Cr(4)-O(1) bond length is 2.09 Å. The Cr(4)-O(10) bond length is 2.07 Å. The Cr(4)-O(12) bond length is 2.08 Å. The Cr(4)-O(3) bond length is 2.41 Å. The Cr(4)-O(4) bond length is 2.34 Å. The Cr(4)-O(5) bond length is 2.30 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(14), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(4)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid,  a cornercorner with one Cr(3)O5 square pyramid, and  an edgeedge with one Cr(4)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. The P(1)-O(14) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.54 Å. The P(1)-O(4) bond length is 1.57 Å. The P(1)-O(5) bond length is 1.59 Å. In the second P site, P(2) is bonded to one O(2), one O(6), and two equivalent O(1) atoms to form PO4 tetrahedra that share corners with two equivalent Cr(4)O6 octahedra and edges with two equivalent Cr(2)O5 square pyramids. The corner-sharing octahedral tilt angles are 53°. The P(2)-O(2) bond length is 1.49 Å. The P(2)-O(6) bond length is 1.59 Å. Both P(2)-O(1) bond lengths are 1.57 Å. In the third P site, P(3) is bonded to one O(11), one O(7), and two equivalent O(13) atoms to form PO4 tetrahedra that share  a cornercorner with one Cr(3)O5 square pyramid and corners with two equivalent Cr(2)O5 square pyramids. The P(3)-O(11) bond length is 1.51 Å. The P(3)-O(7) bond length is 1.57 Å. Both P(3)-O(13) bond lengths are 1.57 Å. In the fourth P site, P(4) is bonded to one O(10), one O(12), one O(8), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Cr(4)O6 octahedra,  a cornercorner with one Cr(2)O5 square pyramid, and  a cornercorner with one Cr(3)O5 square pyramid. The corner-sharing octahedral tilt angles range from 43-52°. The P(4)-O(10) bond length is 1.55 Å. The P(4)-O(12) bond length is 1.56 Å. The P(4)-O(8) bond length is 1.59 Å. The P(4)-O(9) bond length is 1.54 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Cr(2), one Cr(4), and one P(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Li(1) and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Cr(1), one Cr(4), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Li(3), one Cr(3), one Cr(4), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted tetrahedral geometry to one Li(2), one Cr(2), one Cr(4), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Cr(2) and one P(2) atom. In the seventh O site, O(7) is bonded in a trigonal non-coplanar geometry to two equivalent Li(2) and one P(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Cr(1), one Cr(3), and one P(4) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Li(2), one Cr(2), and one P(4) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Li(1), one Cr(4), and one P(4) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one Cr(3) and one P(3) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Cr(1), one Cr(4), and one P(4) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Cr(1), one Cr(2), and one P(3) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Cr(1) and one P(1) atom.