Cu2PO4 crystallizes in the triclinic P-1 space group. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(1), one O(2), one O(6), and two equivalent O(3) atoms to form distorted CuO5 trigonal bipyramids that share  a cornercorner with one P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and  an edgeedge with one Cu(1)O5 trigonal bipyramid. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(4), one O(7), and one O(8) atom. In the third Cu site, Cu(3) is bonded in a 3-coordinate geometry to one O(2), one O(4), and one O(7) atom. In the fourth Cu site, Cu(4) is bonded in a distorted T-shaped geometry to one O(5), one O(6), and one O(8) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(4), one O(5), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Cu(1)O5 trigonal bipyramid. In the second P site, P(2) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with four equivalent Cu(1)O5 trigonal bipyramids. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Cu(1), one Cu(2), and one P(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Cu(1), one Cu(2), one Cu(3), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Cu(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Cu(2), one Cu(3), and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Cu(4) and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(4), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Cu(2), one Cu(3), and one P(2) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Cu(2), one Cu(4), and one P(1) atom.
Cu2PO4 crystallizes in the triclinic P-1 space group. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(1), one O(2), one O(6), and two equivalent O(3) atoms to form distorted CuO5 trigonal bipyramids that share  a cornercorner with one P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and  an edgeedge with one Cu(1)O5 trigonal bipyramid. The Cu(1)-O(1) bond length is 1.95 Å. The Cu(1)-O(2) bond length is 2.40 Å. The Cu(1)-O(6) bond length is 1.89 Å. There is one shorter (1.95 Å) and one longer (1.96 Å) Cu(1)-O(3) bond length. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(4), one O(7), and one O(8) atom. The Cu(2)-O(1) bond length is 1.95 Å. The Cu(2)-O(2) bond length is 2.63 Å. The Cu(2)-O(4) bond length is 1.96 Å. The Cu(2)-O(7) bond length is 2.02 Å. The Cu(2)-O(8) bond length is 2.03 Å. In the third Cu site, Cu(3) is bonded in a 3-coordinate geometry to one O(2), one O(4), and one O(7) atom. The Cu(3)-O(2) bond length is 1.90 Å. The Cu(3)-O(4) bond length is 1.93 Å. The Cu(3)-O(7) bond length is 2.12 Å. In the fourth Cu site, Cu(4) is bonded in a distorted T-shaped geometry to one O(5), one O(6), and one O(8) atom. The Cu(4)-O(5) bond length is 1.85 Å. The Cu(4)-O(6) bond length is 2.52 Å. The Cu(4)-O(8) bond length is 1.89 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(4), one O(5), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Cu(1)O5 trigonal bipyramid. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(4) bond length is 1.56 Å. The P(1)-O(5) bond length is 1.50 Å. The P(1)-O(8) bond length is 1.57 Å. In the second P site, P(2) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with four equivalent Cu(1)O5 trigonal bipyramids. The P(2)-O(1) bond length is 1.56 Å. The P(2)-O(3) bond length is 1.55 Å. The P(2)-O(6) bond length is 1.51 Å. The P(2)-O(7) bond length is 1.53 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Cu(1), one Cu(2), and one P(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Cu(1), one Cu(2), one Cu(3), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Cu(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Cu(2), one Cu(3), and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Cu(4) and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(4), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Cu(2), one Cu(3), and one P(2) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Cu(2), one Cu(4), and one P(1) atom.