Li7Cr3Fe(PO4)6 crystallizes in the trigonal R3 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(2), one O(5), and two equivalent O(3) atoms. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(6), and two equivalent O(7) atoms. In the third Li site, Li(3) is bonded in a 3-coordinate geometry to three equivalent O(2) and three equivalent O(6) atoms. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. In the second Cr site, Cr(2) is bonded to three equivalent O(1) and three equivalent O(7) atoms to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. In the third Cr site, Cr(3) is bonded to three equivalent O(3) and three equivalent O(8) atoms to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. Fe(1) is bonded to three equivalent O(4) and three equivalent O(6) atoms to form distorted FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra, and  a cornercorner with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-40°. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra, and  a cornercorner with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-42°. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Li(2), one Cr(2), and one P(2) atom. In the second O site, O(8) is bonded in a bent 150 degrees geometry to one Cr(3) and one P(2) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(2) and one P(1) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Li(1), one Li(3), one Cr(1), and one P(1) atom. In the fifth O site, O(3) is bonded to two equivalent Li(1), one Cr(3), and one P(1) atom to form distorted edge-sharing OLi2CrP trigonal pyramids. In the sixth O site, O(4) is bonded in a 3-coordinate geometry to one Li(2), one Fe(1), and one P(1) atom. In the seventh O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(1), one Cr(1), and one P(2) atom. In the eighth O site, O(6) is bonded in a 5-coordinate geometry to one Li(3), two equivalent Li(2), one Fe(1), and one P(2) atom.
Li7Cr3Fe(PO4)6 crystallizes in the trigonal R3 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(2), one O(5), and two equivalent O(3) atoms. The Li(1)-O(2) bond length is 2.34 Å. The Li(1)-O(5) bond length is 2.08 Å. There is one shorter (2.04 Å) and one longer (2.24 Å) Li(1)-O(3) bond length. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(6), and two equivalent O(7) atoms. The Li(2)-O(4) bond length is 2.03 Å. There is one shorter (2.19 Å) and one longer (2.61 Å) Li(2)-O(6) bond length. There is one shorter (2.08 Å) and one longer (2.56 Å) Li(2)-O(7) bond length. In the third Li site, Li(3) is bonded in a 3-coordinate geometry to three equivalent O(2) and three equivalent O(6) atoms. All Li(3)-O(2) bond lengths are 2.65 Å. All Li(3)-O(6) bond lengths are 2.11 Å. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Cr(1)-O(2) bond lengths are 2.03 Å. All Cr(1)-O(5) bond lengths are 2.04 Å. In the second Cr site, Cr(2) is bonded to three equivalent O(1) and three equivalent O(7) atoms to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Cr(2)-O(1) bond lengths are 1.99 Å. All Cr(2)-O(7) bond lengths are 2.04 Å. In the third Cr site, Cr(3) is bonded to three equivalent O(3) and three equivalent O(8) atoms to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Cr(3)-O(3) bond lengths are 2.01 Å. All Cr(3)-O(8) bond lengths are 1.95 Å. Fe(1) is bonded to three equivalent O(4) and three equivalent O(6) atoms to form distorted FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Fe(1)-O(4) bond lengths are 2.03 Å. All Fe(1)-O(6) bond lengths are 2.18 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra, and  a cornercorner with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-40°. The P(1)-O(1) bond length is 1.53 Å. The P(1)-O(2) bond length is 1.56 Å. The P(1)-O(3) bond length is 1.57 Å. The P(1)-O(4) bond length is 1.54 Å. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Cr(3)O6 octahedra, and  a cornercorner with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-42°. The P(2)-O(5) bond length is 1.57 Å. The P(2)-O(6) bond length is 1.55 Å. The P(2)-O(7) bond length is 1.57 Å. The P(2)-O(8) bond length is 1.52 Å. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Li(2), one Cr(2), and one P(2) atom. In the second O site, O(8) is bonded in a bent 150 degrees geometry to one Cr(3) and one P(2) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(2) and one P(1) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Li(1), one Li(3), one Cr(1), and one P(1) atom. In the fifth O site, O(3) is bonded to two equivalent Li(1), one Cr(3), and one P(1) atom to form distorted edge-sharing OLi2CrP trigonal pyramids. In the sixth O site, O(4) is bonded in a 3-coordinate geometry to one Li(2), one Fe(1), and one P(1) atom. In the seventh O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(1), one Cr(1), and one P(2) atom. In the eighth O site, O(6) is bonded in a 5-coordinate geometry to one Li(3), two equivalent Li(2), one Fe(1), and one P(2) atom.