LiCuP2O7 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and one O(6) atom. Cu(1) is bonded to one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted CuO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Cu(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Li(1) and one P(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Cu(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Cu(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Li(1), one Cu(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Cu(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(1) atom.
LiCuP2O7 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Li(1)-O(2) bond length is 1.99 Å. The Li(1)-O(3) bond length is 2.23 Å. The Li(1)-O(4) bond length is 2.03 Å. The Li(1)-O(5) bond length is 2.56 Å. The Li(1)-O(6) bond length is 2.33 Å. Cu(1) is bonded to one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted CuO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. The Cu(1)-O(3) bond length is 1.86 Å. The Cu(1)-O(4) bond length is 2.47 Å. The Cu(1)-O(5) bond length is 1.93 Å. The Cu(1)-O(6) bond length is 1.88 Å. The Cu(1)-O(7) bond length is 1.91 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(4), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with three equivalent Cu(1)O5 trigonal bipyramids. The P(1)-O(1) bond length is 1.62 Å. The P(1)-O(3) bond length is 1.56 Å. The P(1)-O(4) bond length is 1.50 Å. The P(1)-O(7) bond length is 1.56 Å. In the second P site, P(2) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. The P(2)-O(1) bond length is 1.64 Å. The P(2)-O(2) bond length is 1.48 Å. The P(2)-O(5) bond length is 1.57 Å. The P(2)-O(6) bond length is 1.57 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Li(1) and one P(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Li(1), one Cu(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Li(1), one Cu(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Li(1), one Cu(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Cu(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(1) atom.