Li2CuPO4 crystallizes in the orthorhombic Pnma space group. Li(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form LiO4 tetrahedra that share corners with four equivalent Li(1)O4 tetrahedra and corners with four equivalent P(1)O4 tetrahedra. Cu(1) is bonded in a 3-coordinate geometry to one O(2) and two equivalent O(3) atoms. P(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with eight equivalent Li(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Li(1) and one P(1) atom. In the second O site, O(2) is bonded to two equivalent Li(1), one Cu(1), and one P(1) atom to form distorted corner-sharing OLi2CuP trigonal pyramids. In the third O site, O(3) is bonded to two equivalent Li(1), one Cu(1), and one P(1) atom to form distorted corner-sharing OLi2CuP trigonal pyramids.
Li2CuPO4 crystallizes in the orthorhombic Pnma space group. Li(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form LiO4 tetrahedra that share corners with four equivalent Li(1)O4 tetrahedra and corners with four equivalent P(1)O4 tetrahedra. The Li(1)-O(1) bond length is 1.96 Å. The Li(1)-O(2) bond length is 1.96 Å. There is one shorter (2.03 Å) and one longer (2.06 Å) Li(1)-O(3) bond length. Cu(1) is bonded in a 3-coordinate geometry to one O(2) and two equivalent O(3) atoms. The Cu(1)-O(2) bond length is 2.34 Å. Both Cu(1)-O(3) bond lengths are 1.96 Å. P(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with eight equivalent Li(1)O4 tetrahedra. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(2) bond length is 1.55 Å. Both P(1)-O(3) bond lengths are 1.57 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Li(1) and one P(1) atom. In the second O site, O(2) is bonded to two equivalent Li(1), one Cu(1), and one P(1) atom to form distorted corner-sharing OLi2CuP trigonal pyramids. In the third O site, O(3) is bonded to two equivalent Li(1), one Cu(1), and one P(1) atom to form distorted corner-sharing OLi2CuP trigonal pyramids.