Cu3Sn(PO4)4 crystallizes in the monoclinic Pm space group. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(12), one O(4), and two equivalent O(2) atoms. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(3), one O(7), and two equivalent O(5) atoms. In the third Cu site, Cu(3) is bonded in a rectangular see-saw-like geometry to one O(10), one O(6), and two equivalent O(8) atoms. Sn(1) is bonded to one O(1), one O(9), two equivalent O(11), and two equivalent O(5) atoms to form distorted SnO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(10), and two equivalent O(2) atoms to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles are 45°. In the second P site, P(2) is bonded to one O(6), one O(9), and two equivalent O(5) atoms to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O6 octahedra and  an edgeedge with one Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles are 39°. In the third P site, P(3) is bonded in a tetrahedral geometry to one O(4), one O(7), and two equivalent O(8) atoms. In the fourth P site, P(4) is bonded to one O(12), one O(3), and two equivalent O(11) atoms to form PO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Sn(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Cu(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Cu(2) and one P(4) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(3) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Cu(2), one Sn(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Cu(3) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Cu(2) and one P(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Cu(3) and one P(3) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Sn(1) and one P(2) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Cu(3) and one P(1) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Sn(1) and one P(4) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(4) atom.
Cu3Sn(PO4)4 crystallizes in the monoclinic Pm space group. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(12), one O(4), and two equivalent O(2) atoms. The Cu(1)-O(12) bond length is 1.87 Å. The Cu(1)-O(4) bond length is 1.88 Å. Both Cu(1)-O(2) bond lengths are 1.89 Å. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to one O(3), one O(7), and two equivalent O(5) atoms. The Cu(2)-O(3) bond length is 1.87 Å. The Cu(2)-O(7) bond length is 1.86 Å. Both Cu(2)-O(5) bond lengths are 1.95 Å. In the third Cu site, Cu(3) is bonded in a rectangular see-saw-like geometry to one O(10), one O(6), and two equivalent O(8) atoms. The Cu(3)-O(10) bond length is 1.89 Å. The Cu(3)-O(6) bond length is 1.88 Å. Both Cu(3)-O(8) bond lengths are 1.89 Å. Sn(1) is bonded to one O(1), one O(9), two equivalent O(11), and two equivalent O(5) atoms to form distorted SnO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with two equivalent P(4)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The Sn(1)-O(1) bond length is 2.02 Å. The Sn(1)-O(9) bond length is 2.06 Å. Both Sn(1)-O(11) bond lengths are 2.06 Å. Both Sn(1)-O(5) bond lengths are 2.22 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(10), and two equivalent O(2) atoms to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles are 45°. The P(1)-O(1) bond length is 1.57 Å. The P(1)-O(10) bond length is 1.55 Å. Both P(1)-O(2) bond lengths are 1.55 Å. In the second P site, P(2) is bonded to one O(6), one O(9), and two equivalent O(5) atoms to form PO4 tetrahedra that share  a cornercorner with one Sn(1)O6 octahedra and  an edgeedge with one Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles are 39°. The P(2)-O(6) bond length is 1.52 Å. The P(2)-O(9) bond length is 1.53 Å. Both P(2)-O(5) bond lengths are 1.59 Å. In the third P site, P(3) is bonded in a tetrahedral geometry to one O(4), one O(7), and two equivalent O(8) atoms. The P(3)-O(4) bond length is 1.55 Å. The P(3)-O(7) bond length is 1.55 Å. Both P(3)-O(8) bond lengths are 1.56 Å. In the fourth P site, P(4) is bonded to one O(12), one O(3), and two equivalent O(11) atoms to form PO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. The P(4)-O(12) bond length is 1.54 Å. The P(4)-O(3) bond length is 1.54 Å. Both P(4)-O(11) bond lengths are 1.57 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Sn(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Cu(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Cu(2) and one P(4) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(3) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Cu(2), one Sn(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Cu(3) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Cu(2) and one P(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Cu(3) and one P(3) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Sn(1) and one P(2) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Cu(3) and one P(1) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Sn(1) and one P(4) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Cu(1) and one P(4) atom.