Li2Cr2O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(4), one O(6), and one O(9) atom to form LiO4 trigonal pyramids that share  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Cr(1)O4 tetrahedra,  a cornercorner with one Cr(3)O4 tetrahedra, and corners with two equivalent Cr(2)O4 tetrahedra. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one O(3), one O(5), one O(6), and one O(8) atom. In the third Li site, Li(3) is bonded in a 5-coordinate geometry to one O(11), one O(14), one O(4), one O(5), and one O(7) atom. In the fourth Li site, Li(4) is bonded to one O(12), one O(13), one O(14), and one O(9) atom to form distorted LiO4 tetrahedra that share corners with two equivalent Cr(4)O4 tetrahedra, corners with three equivalent Cr(3)O4 tetrahedra, and  a cornercorner with one Li(1)O4 trigonal pyramid. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form CrO4 tetrahedra that share  a cornercorner with one Cr(2)O4 tetrahedra and  a cornercorner with one Li(1)O4 trigonal pyramid. In the second Cr site, Cr(2) is bonded to one O(1), one O(2), one O(6), and one O(7) atom to form CrO4 tetrahedra that share  a cornercorner with one Cr(1)O4 tetrahedra and corners with two equivalent Li(1)O4 trigonal pyramids. In the third Cr site, Cr(3) is bonded to one O(12), one O(13), one O(8), and one O(9) atom to form CrO4 tetrahedra that share  a cornercorner with one Cr(4)O4 tetrahedra, corners with three equivalent Li(4)O4 tetrahedra, and  a cornercorner with one Li(1)O4 trigonal pyramid. In the fourth Cr site, Cr(4) is bonded to one O(10), one O(11), one O(13), and one O(14) atom to form CrO4 tetrahedra that share  a cornercorner with one Cr(3)O4 tetrahedra and corners with two equivalent Li(4)O4 tetrahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cr(1) and one Cr(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Li(1) and one Cr(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Li(2) and one Cr(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Li(3), and one Cr(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Li(2), one Li(3), and one Cr(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Cr(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Li(3) and one Cr(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Li(2) and one Cr(3) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Li(1), one Li(4), and one Cr(3) atom. In the tenth O site, O(10) is bonded in a single-bond geometry to one Cr(4) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Li(3) and one Cr(4) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Li(4) and one Cr(3) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Li(4), one Cr(3), and one Cr(4) atom. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Li(3), one Li(4), and one Cr(4) atom.
Li2Cr2O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(4), one O(6), and one O(9) atom to form LiO4 trigonal pyramids that share  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Cr(1)O4 tetrahedra,  a cornercorner with one Cr(3)O4 tetrahedra, and corners with two equivalent Cr(2)O4 tetrahedra. The Li(1)-O(2) bond length is 1.99 Å. The Li(1)-O(4) bond length is 2.16 Å. The Li(1)-O(6) bond length is 1.97 Å. The Li(1)-O(9) bond length is 2.19 Å. In the second Li site, Li(2) is bonded in a 4-coordinate geometry to one O(3), one O(5), one O(6), and one O(8) atom. The Li(2)-O(3) bond length is 2.02 Å. The Li(2)-O(5) bond length is 2.15 Å. The Li(2)-O(6) bond length is 2.16 Å. The Li(2)-O(8) bond length is 2.06 Å. In the third Li site, Li(3) is bonded in a 5-coordinate geometry to one O(11), one O(14), one O(4), one O(5), and one O(7) atom. The Li(3)-O(11) bond length is 2.01 Å. The Li(3)-O(14) bond length is 2.12 Å. The Li(3)-O(4) bond length is 2.36 Å. The Li(3)-O(5) bond length is 2.47 Å. The Li(3)-O(7) bond length is 2.44 Å. In the fourth Li site, Li(4) is bonded to one O(12), one O(13), one O(14), and one O(9) atom to form distorted LiO4 tetrahedra that share corners with two equivalent Cr(4)O4 tetrahedra, corners with three equivalent Cr(3)O4 tetrahedra, and  a cornercorner with one Li(1)O4 trigonal pyramid. The Li(4)-O(12) bond length is 2.07 Å. The Li(4)-O(13) bond length is 2.38 Å. The Li(4)-O(14) bond length is 2.05 Å. The Li(4)-O(9) bond length is 2.05 Å. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form CrO4 tetrahedra that share  a cornercorner with one Cr(2)O4 tetrahedra and  a cornercorner with one Li(1)O4 trigonal pyramid. The Cr(1)-O(1) bond length is 1.78 Å. The Cr(1)-O(3) bond length is 1.63 Å. The Cr(1)-O(4) bond length is 1.64 Å. The Cr(1)-O(5) bond length is 1.64 Å. In the second Cr site, Cr(2) is bonded to one O(1), one O(2), one O(6), and one O(7) atom to form CrO4 tetrahedra that share  a cornercorner with one Cr(1)O4 tetrahedra and corners with two equivalent Li(1)O4 trigonal pyramids. The Cr(2)-O(1) bond length is 1.78 Å. The Cr(2)-O(2) bond length is 1.64 Å. The Cr(2)-O(6) bond length is 1.65 Å. The Cr(2)-O(7) bond length is 1.62 Å. In the third Cr site, Cr(3) is bonded to one O(12), one O(13), one O(8), and one O(9) atom to form CrO4 tetrahedra that share  a cornercorner with one Cr(4)O4 tetrahedra, corners with three equivalent Li(4)O4 tetrahedra, and  a cornercorner with one Li(1)O4 trigonal pyramid. The Cr(3)-O(12) bond length is 1.64 Å. The Cr(3)-O(13) bond length is 1.80 Å. The Cr(3)-O(8) bond length is 1.62 Å. The Cr(3)-O(9) bond length is 1.66 Å. In the fourth Cr site, Cr(4) is bonded to one O(10), one O(11), one O(13), and one O(14) atom to form CrO4 tetrahedra that share  a cornercorner with one Cr(3)O4 tetrahedra and corners with two equivalent Li(4)O4 tetrahedra. The Cr(4)-O(10) bond length is 1.61 Å. The Cr(4)-O(11) bond length is 1.63 Å. The Cr(4)-O(13) bond length is 1.82 Å. The Cr(4)-O(14) bond length is 1.66 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cr(1) and one Cr(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Li(1) and one Cr(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Li(2) and one Cr(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Li(3), and one Cr(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Li(2), one Li(3), and one Cr(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Cr(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Li(3) and one Cr(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Li(2) and one Cr(3) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Li(1), one Li(4), and one Cr(3) atom. In the tenth O site, O(10) is bonded in a single-bond geometry to one Cr(4) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Li(3) and one Cr(4) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Li(4) and one Cr(3) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one Li(4), one Cr(3), and one Cr(4) atom. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Li(3), one Li(4), and one Cr(4) atom.