K2Cu3Ge5O14 crystallizes in the triclinic P-1 space group. K(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(4), one O(6), one O(7), and two equivalent O(3) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(2), one O(6), one O(7), and two equivalent O(5) atoms to form distorted CuO5 square pyramids that share corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra,  an edgeedge with one Cu(2)O6 octahedra,  an edgeedge with one Ge(3)O6 octahedra, and  an edgeedge with one Cu(1)O5 square pyramid. In the second Cu site, Cu(2) is bonded to two equivalent O(4), two equivalent O(6), and two equivalent O(7) atoms to form distorted CuO6 octahedra that share corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, edges with two equivalent Ge(3)O6 octahedra, and edges with two equivalent Cu(1)O5 square pyramids. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form GeO4 tetrahedra that share  a cornercorner with one Cu(2)O6 octahedra,  a cornercorner with one Ge(3)O6 octahedra, corners with two equivalent Cu(1)O5 square pyramids, and corners with two equivalent Ge(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-62°. In the second Ge site, Ge(2) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form GeO4 tetrahedra that share  a cornercorner with one Cu(2)O6 octahedra,  a cornercorner with one Ge(3)O6 octahedra, corners with two equivalent Cu(1)O5 square pyramids, and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-60°. In the third Ge site, Ge(3) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(7) atoms to form GeO6 octahedra that share corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, edges with two equivalent Cu(2)O6 octahedra, and edges with two equivalent Cu(1)O5 square pyramids. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one K(1), one Ge(1), and one Ge(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one Cu(1), one Ge(1), and one Ge(3) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent K(1), one Ge(1), and one Ge(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one K(1), one Cu(2), one Ge(2), and one Ge(3) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Cu(1) and one Ge(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(1), one Cu(1), one Cu(2), and one Ge(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one K(1), one Cu(1), one Cu(2), and one Ge(3) atom.
K2Cu3Ge5O14 crystallizes in the triclinic P-1 space group. K(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(4), one O(6), one O(7), and two equivalent O(3) atoms. The K(1)-O(1) bond length is 3.09 Å. The K(1)-O(2) bond length is 2.82 Å. The K(1)-O(4) bond length is 3.01 Å. The K(1)-O(6) bond length is 3.17 Å. The K(1)-O(7) bond length is 3.00 Å. There is one shorter (2.74 Å) and one longer (3.13 Å) K(1)-O(3) bond length. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(2), one O(6), one O(7), and two equivalent O(5) atoms to form distorted CuO5 square pyramids that share corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra,  an edgeedge with one Cu(2)O6 octahedra,  an edgeedge with one Ge(3)O6 octahedra, and  an edgeedge with one Cu(1)O5 square pyramid. The Cu(1)-O(2) bond length is 2.40 Å. The Cu(1)-O(6) bond length is 1.98 Å. The Cu(1)-O(7) bond length is 1.93 Å. There is one shorter (1.93 Å) and one longer (1.98 Å) Cu(1)-O(5) bond length. In the second Cu site, Cu(2) is bonded to two equivalent O(4), two equivalent O(6), and two equivalent O(7) atoms to form distorted CuO6 octahedra that share corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, edges with two equivalent Ge(3)O6 octahedra, and edges with two equivalent Cu(1)O5 square pyramids. Both Cu(2)-O(4) bond lengths are 2.57 Å. Both Cu(2)-O(6) bond lengths are 1.99 Å. Both Cu(2)-O(7) bond lengths are 1.94 Å. There are three inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form GeO4 tetrahedra that share  a cornercorner with one Cu(2)O6 octahedra,  a cornercorner with one Ge(3)O6 octahedra, corners with two equivalent Cu(1)O5 square pyramids, and corners with two equivalent Ge(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-62°. The Ge(1)-O(1) bond length is 1.81 Å. The Ge(1)-O(2) bond length is 1.76 Å. The Ge(1)-O(3) bond length is 1.79 Å. The Ge(1)-O(6) bond length is 1.77 Å. In the second Ge site, Ge(2) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form GeO4 tetrahedra that share  a cornercorner with one Cu(2)O6 octahedra,  a cornercorner with one Ge(3)O6 octahedra, corners with two equivalent Cu(1)O5 square pyramids, and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-60°. The Ge(2)-O(1) bond length is 1.81 Å. The Ge(2)-O(3) bond length is 1.79 Å. The Ge(2)-O(4) bond length is 1.76 Å. The Ge(2)-O(5) bond length is 1.76 Å. In the third Ge site, Ge(3) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(7) atoms to form GeO6 octahedra that share corners with two equivalent Ge(1)O4 tetrahedra, corners with two equivalent Ge(2)O4 tetrahedra, edges with two equivalent Cu(2)O6 octahedra, and edges with two equivalent Cu(1)O5 square pyramids. Both Ge(3)-O(2) bond lengths are 1.96 Å. Both Ge(3)-O(4) bond lengths are 1.99 Å. Both Ge(3)-O(7) bond lengths are 1.88 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one K(1), one Ge(1), and one Ge(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one Cu(1), one Ge(1), and one Ge(3) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent K(1), one Ge(1), and one Ge(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one K(1), one Cu(2), one Ge(2), and one Ge(3) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Cu(1) and one Ge(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(1), one Cu(1), one Cu(2), and one Ge(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one K(1), one Cu(1), one Cu(2), and one Ge(3) atom.