Li2CrP2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a trigonal non-coplanar geometry to one O(3), one O(4), and one O(5) atom. In the second Li site, Li(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form distorted LiO4 trigonal pyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent Cr(1)O5 trigonal bipyramids. Cr(1) is bonded to one O(1), one O(4), one O(6), and two equivalent O(2) atoms to form distorted CrO5 trigonal bipyramids that share  a cornercorner with one P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, corners with two equivalent Li(2)O4 trigonal pyramids, and  an edgeedge with one Cr(1)O5 trigonal bipyramid. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with four equivalent Cr(1)O5 trigonal bipyramids, and corners with two equivalent Li(2)O4 trigonal pyramids. In the second P site, P(2) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one Cr(1)O5 trigonal bipyramid, and corners with two equivalent Li(2)O4 trigonal pyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(2), one Cr(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Cr(1) and one P(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Cr(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(2), one Cr(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom.
Li2CrP2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a trigonal non-coplanar geometry to one O(3), one O(4), and one O(5) atom. The Li(1)-O(3) bond length is 1.98 Å. The Li(1)-O(4) bond length is 2.00 Å. The Li(1)-O(5) bond length is 1.98 Å. In the second Li site, Li(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form distorted LiO4 trigonal pyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent Cr(1)O5 trigonal bipyramids. The Li(2)-O(1) bond length is 2.00 Å. The Li(2)-O(3) bond length is 2.01 Å. The Li(2)-O(5) bond length is 2.12 Å. The Li(2)-O(6) bond length is 2.11 Å. Cr(1) is bonded to one O(1), one O(4), one O(6), and two equivalent O(2) atoms to form distorted CrO5 trigonal bipyramids that share  a cornercorner with one P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, corners with two equivalent Li(2)O4 trigonal pyramids, and  an edgeedge with one Cr(1)O5 trigonal bipyramid. The Cr(1)-O(1) bond length is 2.05 Å. The Cr(1)-O(4) bond length is 2.07 Å. The Cr(1)-O(6) bond length is 2.40 Å. There is one shorter (2.08 Å) and one longer (2.11 Å) Cr(1)-O(2) bond length. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra, corners with four equivalent Cr(1)O5 trigonal bipyramids, and corners with two equivalent Li(2)O4 trigonal pyramids. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(2) bond length is 1.57 Å. The P(1)-O(6) bond length is 1.51 Å. The P(1)-O(7) bond length is 1.61 Å. In the second P site, P(2) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one Cr(1)O5 trigonal bipyramid, and corners with two equivalent Li(2)O4 trigonal pyramids. The P(2)-O(3) bond length is 1.52 Å. The P(2)-O(4) bond length is 1.55 Å. The P(2)-O(5) bond length is 1.53 Å. The P(2)-O(7) bond length is 1.65 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Li(2), one Cr(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Cr(1) and one P(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Cr(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Li(2), one Cr(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom.