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 rectangular see-saw-like geometry to two equivalent O(10) and two equivalent O(5) atoms. In the second Li site, Li(2) is bonded in a distorted single-bond geometry to one O(7) and one O(8) atom. In the third Li site, Li(3) is bonded in a distorted see-saw-like geometry to one O(6), one O(7), one O(8), and one O(9) atom. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(10), one O(12), one O(13), one O(14), and one O(2) atom to form distorted CrO5 trigonal bipyramids that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one Cr(4)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 69°. In the second Cr site, Cr(2) is bonded to one O(11), one O(3), two equivalent O(10), and two equivalent O(5) atoms to form CrO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, corners with two equivalent Cr(1)O5 trigonal bipyramids, and corners with two equivalent Cr(4)O5 trigonal bipyramids. In the third Cr site, Cr(3) is bonded in a 4-coordinate geometry to one O(13), one O(2), one O(4), one O(6), and one O(9) atom. In the fourth Cr site, Cr(4) is bonded to one O(1), one O(12), one O(2), one O(4), and one O(5) atom to form distorted CrO5 trigonal bipyramids that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one Cr(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 70°. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(14), one O(2), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra, corners with two equivalent Cr(1)O5 trigonal bipyramids, and corners with two equivalent Cr(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 55°. In the second P site, P(2) is bonded to one O(3), one O(7), and two equivalent O(4) atoms to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra and corners with two equivalent Cr(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 25°. In the third P site, P(3) is bonded to one O(11), one O(8), and two equivalent O(13) atoms to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra and corners with two equivalent Cr(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 25°. In the fourth P site, P(4) is bonded to one O(1), one O(10), one O(12), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra, corners with two equivalent Cr(1)O5 trigonal bipyramids, and corners with two equivalent Cr(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 57°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Cr(4) and one P(4) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Cr(1), one Cr(3), one Cr(4), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(2) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Cr(3), one Cr(4), and one P(2) atom. In the fifth O site, O(5) is bonded to one Li(1), one Cr(2), one Cr(4), and one P(1) atom to form a mixture of distorted corner and edge-sharing OLiCr2P tetrahedra. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(3), one Cr(3), and one P(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Li(2), two equivalent Li(3), and one P(2) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Li(2), two equivalent Li(3), and one P(3) atom. In the ninth O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Li(3), one Cr(3), and one P(4) atom. In the tenth O site, O(10) is bonded to one Li(1), one Cr(1), one Cr(2), and one P(4) atom to form a mixture of corner and edge-sharing OLiCr2P tetrahedra. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Cr(2) 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 trigonal planar geometry to one Cr(1), one Cr(3), and one P(3) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 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 rectangular see-saw-like geometry to two equivalent O(10) and two equivalent O(5) atoms. Both Li(1)-O(10) bond lengths are 2.27 Å. Both Li(1)-O(5) bond lengths are 2.41 Å. In the second Li site, Li(2) is bonded in a distorted single-bond geometry to one O(7) and one O(8) atom. The Li(2)-O(7) bond length is 1.97 Å. The Li(2)-O(8) bond length is 2.53 Å. In the third Li site, Li(3) is bonded in a distorted see-saw-like geometry to one O(6), one O(7), one O(8), and one O(9) atom. The Li(3)-O(6) bond length is 2.09 Å. The Li(3)-O(7) bond length is 2.51 Å. The Li(3)-O(8) bond length is 1.98 Å. The Li(3)-O(9) bond length is 1.91 Å. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(10), one O(12), one O(13), one O(14), and one O(2) atom to form distorted CrO5 trigonal bipyramids that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one Cr(4)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 69°. The Cr(1)-O(10) bond length is 2.15 Å. The Cr(1)-O(12) bond length is 2.25 Å. The Cr(1)-O(13) bond length is 2.25 Å. The Cr(1)-O(14) bond length is 2.03 Å. The Cr(1)-O(2) bond length is 2.10 Å. In the second Cr site, Cr(2) is bonded to one O(11), one O(3), two equivalent O(10), and two equivalent O(5) atoms to form CrO6 octahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, corners with two equivalent Cr(1)O5 trigonal bipyramids, and corners with two equivalent Cr(4)O5 trigonal bipyramids. The Cr(2)-O(11) bond length is 2.03 Å. The Cr(2)-O(3) bond length is 2.04 Å. Both Cr(2)-O(10) bond lengths are 2.26 Å. Both Cr(2)-O(5) bond lengths are 2.24 Å. In the third Cr site, Cr(3) is bonded in a 4-coordinate geometry to one O(13), one O(2), one O(4), one O(6), and one O(9) atom. The Cr(3)-O(13) bond length is 2.04 Å. The Cr(3)-O(2) bond length is 2.64 Å. The Cr(3)-O(4) bond length is 2.08 Å. The Cr(3)-O(6) bond length is 2.10 Å. The Cr(3)-O(9) bond length is 2.10 Å. In the fourth Cr site, Cr(4) is bonded to one O(1), one O(12), one O(2), one O(4), and one O(5) atom to form distorted CrO5 trigonal bipyramids that share  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one Cr(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 70°. The Cr(4)-O(1) bond length is 2.04 Å. The Cr(4)-O(12) bond length is 2.09 Å. The Cr(4)-O(2) bond length is 2.27 Å. The Cr(4)-O(4) bond length is 2.20 Å. The Cr(4)-O(5) bond length is 2.12 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(14), one O(2), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra, corners with two equivalent Cr(1)O5 trigonal bipyramids, and corners with two equivalent Cr(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 55°. The P(1)-O(14) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.57 Å. The P(1)-O(5) bond length is 1.58 Å. The P(1)-O(6) bond length is 1.57 Å. In the second P site, P(2) is bonded to one O(3), one O(7), and two equivalent O(4) atoms to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra and corners with two equivalent Cr(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 25°. The P(2)-O(3) bond length is 1.53 Å. The P(2)-O(7) bond length is 1.55 Å. Both P(2)-O(4) bond lengths are 1.57 Å. In the third P site, P(3) is bonded to one O(11), one O(8), and two equivalent O(13) atoms to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra and corners with two equivalent Cr(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 25°. The P(3)-O(11) bond length is 1.53 Å. The P(3)-O(8) bond length is 1.56 Å. Both P(3)-O(13) bond lengths are 1.56 Å. In the fourth P site, P(4) is bonded to one O(1), one O(10), one O(12), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra, corners with two equivalent Cr(1)O5 trigonal bipyramids, and corners with two equivalent Cr(4)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 57°. The P(4)-O(1) bond length is 1.53 Å. The P(4)-O(10) bond length is 1.58 Å. The P(4)-O(12) bond length is 1.57 Å. The P(4)-O(9) bond length is 1.57 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Cr(4) and one P(4) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Cr(1), one Cr(3), one Cr(4), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(2) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Cr(3), one Cr(4), and one P(2) atom. In the fifth O site, O(5) is bonded to one Li(1), one Cr(2), one Cr(4), and one P(1) atom to form a mixture of distorted corner and edge-sharing OLiCr2P tetrahedra. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Li(3), one Cr(3), and one P(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Li(2), two equivalent Li(3), and one P(2) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Li(2), two equivalent Li(3), and one P(3) atom. In the ninth O site, O(9) is bonded in a distorted trigonal non-coplanar geometry to one Li(3), one Cr(3), and one P(4) atom. In the tenth O site, O(10) is bonded to one Li(1), one Cr(1), one Cr(2), and one P(4) atom to form a mixture of corner and edge-sharing OLiCr2P tetrahedra. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Cr(2) 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 trigonal planar geometry to one Cr(1), one Cr(3), and one P(3) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 degrees geometry to one Cr(1) and one P(1) atom.