Li2Cr(PO4)2 crystallizes in the monoclinic P2_1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(10), one O(14), one O(7), and one O(9) atom to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles are 73°. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(16), one O(2), one O(3), one O(5), and one O(8) atom. In the third Li site, Li(3) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(14), one O(2), and one O(9) atom. In the fourth Li site, Li(4) is bonded in a 5-coordinate geometry to one O(15), one O(3), one O(4), one O(5), and one O(8) atom. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(10), one O(11), one O(12), one O(15), one O(7), and one O(9) atom 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,  a cornercorner with one Li(1)O5 trigonal bipyramid, and  an edgeedge with one Li(1)O5 trigonal bipyramid. In the second Cr site, Cr(2) is bonded to one O(13), one O(16), one O(2), one O(3), one O(4), and one O(6) atom to form CrO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(12), one O(14), one O(15), and one O(3) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra, and  a cornercorner with one Li(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 47-49°. In the second P site, P(2) is bonded to one O(13), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra, and  a cornercorner with one Li(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 46-51°. In the third P site, P(3) is bonded to one O(2), one O(6), one O(8), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra, and  a cornercorner with one Li(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 47-50°. In the fourth P site, P(4) is bonded to one O(1), one O(10), one O(11), and one O(16) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra, and corners with two equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 48°. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Li(3), and one P(4) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Li(2), one Li(3), one Cr(2), and one P(3) atom. In the third O site, O(3) is bonded in a distorted trigonal pyramidal geometry to one Li(2), one Li(4), one Cr(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(4), one Cr(2), and one P(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(2), one Li(4), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Cr(2) and one P(3) atom. In the seventh O site, O(7) 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(8) is bonded in a 2-coordinate geometry to one Li(2), one Li(4), and one P(3) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Li(1), one Li(3), one Cr(1), and one P(3) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Li(1), one Cr(1), and one P(4) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Li(3), one Cr(1), and one P(4) atom. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one Cr(1) and one P(1) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to one Cr(2) and one P(2) atom. In the fourteenth O site, O(14) is bonded in a distorted T-shaped geometry to one Li(1), one Li(3), and one P(1) atom. In the fifteenth O site, O(15) is bonded in a trigonal non-coplanar geometry to one Li(4), one Cr(1), and one P(1) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Li(2), one Cr(2), and one P(4) atom.
Li2Cr(PO4)2 crystallizes in the monoclinic P2_1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(10), one O(14), one O(7), and one O(9) atom to form distorted LiO5 trigonal bipyramids that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles are 73°. The Li(1)-O(1) bond length is 2.03 Å. The Li(1)-O(10) bond length is 2.39 Å. The Li(1)-O(14) bond length is 1.97 Å. The Li(1)-O(7) bond length is 2.04 Å. The Li(1)-O(9) bond length is 2.24 Å. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(16), one O(2), one O(3), one O(5), and one O(8) atom. The Li(2)-O(16) bond length is 2.12 Å. The Li(2)-O(2) bond length is 2.51 Å. The Li(2)-O(3) bond length is 2.27 Å. The Li(2)-O(5) bond length is 1.98 Å. The Li(2)-O(8) bond length is 1.97 Å. In the third Li site, Li(3) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(14), one O(2), and one O(9) atom. The Li(3)-O(1) bond length is 1.99 Å. The Li(3)-O(11) bond length is 2.23 Å. The Li(3)-O(14) bond length is 2.20 Å. The Li(3)-O(2) bond length is 2.24 Å. The Li(3)-O(9) bond length is 2.36 Å. In the fourth Li site, Li(4) is bonded in a 5-coordinate geometry to one O(15), one O(3), one O(4), one O(5), and one O(8) atom. The Li(4)-O(15) bond length is 2.09 Å. The Li(4)-O(3) bond length is 2.19 Å. The Li(4)-O(4) bond length is 2.30 Å. The Li(4)-O(5) bond length is 2.01 Å. The Li(4)-O(8) bond length is 2.50 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(10), one O(11), one O(12), one O(15), one O(7), and one O(9) atom 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,  a cornercorner with one Li(1)O5 trigonal bipyramid, and  an edgeedge with one Li(1)O5 trigonal bipyramid. The Cr(1)-O(10) bond length is 1.95 Å. The Cr(1)-O(11) bond length is 2.00 Å. The Cr(1)-O(12) bond length is 1.96 Å. The Cr(1)-O(15) bond length is 2.01 Å. The Cr(1)-O(7) bond length is 2.02 Å. The Cr(1)-O(9) bond length is 2.08 Å. In the second Cr site, Cr(2) is bonded to one O(13), one O(16), one O(2), one O(3), one O(4), and one O(6) atom to form CrO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. The Cr(2)-O(13) bond length is 1.94 Å. The Cr(2)-O(16) bond length is 2.01 Å. The Cr(2)-O(2) bond length is 2.02 Å. The Cr(2)-O(3) bond length is 2.04 Å. The Cr(2)-O(4) bond length is 1.99 Å. The Cr(2)-O(6) bond length is 1.95 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(12), one O(14), one O(15), and one O(3) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra, and  a cornercorner with one Li(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 47-49°. The P(1)-O(12) bond length is 1.55 Å. The P(1)-O(14) bond length is 1.52 Å. The P(1)-O(15) bond length is 1.57 Å. The P(1)-O(3) bond length is 1.58 Å. In the second P site, P(2) is bonded to one O(13), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra, and  a cornercorner with one Li(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 46-51°. The P(2)-O(13) bond length is 1.57 Å. The P(2)-O(4) bond length is 1.56 Å. The P(2)-O(5) bond length is 1.53 Å. The P(2)-O(7) bond length is 1.56 Å. In the third P site, P(3) is bonded to one O(2), one O(6), one O(8), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra, and  a cornercorner with one Li(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 47-50°. The P(3)-O(2) bond length is 1.58 Å. The P(3)-O(6) bond length is 1.55 Å. The P(3)-O(8) bond length is 1.52 Å. The P(3)-O(9) bond length is 1.57 Å. In the fourth P site, P(4) is bonded to one O(1), one O(10), one O(11), and one O(16) atom to form PO4 tetrahedra that share  a cornercorner with one Cr(2)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra, and corners with two equivalent Li(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 48°. The P(4)-O(1) bond length is 1.54 Å. The P(4)-O(10) bond length is 1.56 Å. The P(4)-O(11) bond length is 1.56 Å. The P(4)-O(16) bond length is 1.56 Å. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Li(3), and one P(4) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Li(2), one Li(3), one Cr(2), and one P(3) atom. In the third O site, O(3) is bonded in a distorted trigonal pyramidal geometry to one Li(2), one Li(4), one Cr(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(4), one Cr(2), and one P(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(2), one Li(4), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Cr(2) and one P(3) atom. In the seventh O site, O(7) 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(8) is bonded in a 2-coordinate geometry to one Li(2), one Li(4), and one P(3) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Li(1), one Li(3), one Cr(1), and one P(3) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Li(1), one Cr(1), and one P(4) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Li(3), one Cr(1), and one P(4) atom. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one Cr(1) and one P(1) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to one Cr(2) and one P(2) atom. In the fourteenth O site, O(14) is bonded in a distorted T-shaped geometry to one Li(1), one Li(3), and one P(1) atom. In the fifteenth O site, O(15) is bonded in a trigonal non-coplanar geometry to one Li(4), one Cr(1), and one P(1) atom. In the sixteenth O site, O(16) is bonded in a distorted trigonal planar geometry to one Li(2), one Cr(2), and one P(4) atom.