KHfCuF7 crystallizes in the orthorhombic Cmcm space group. K(1) is bonded in a 10-coordinate geometry to one F(2), one F(6), two equivalent F(1), two equivalent F(3), two equivalent F(4), and two equivalent F(5) atoms. Hf(1) is bonded in a 8-coordinate geometry to one F(1), one F(4), two equivalent F(2), two equivalent F(3), and two equivalent F(5) atoms. Cu(1) is bonded to one F(1), one F(4), one F(6), one F(7), and two equivalent F(3) atoms to form distorted corner-sharing CuF6 octahedra. The corner-sharing octahedral tilt angles range from 0-45°. There are seven inequivalent F sites. In the first F site, F(6) is bonded in a 2-coordinate geometry to two equivalent K(1) and two equivalent Cu(1) atoms. In the second F site, F(7) is bonded in a linear geometry to two equivalent Cu(1) atoms. In the third F site, F(1) is bonded to two equivalent K(1), one Hf(1), and one Cu(1) atom to form distorted FK2HfCu tetrahedra that share corners with six equivalent F(5)K2Hf2 tetrahedra and  an edgeedge with one F(1)K2HfCu tetrahedra. In the fourth F site, F(2) is bonded in a distorted bent 120 degrees geometry to one K(1) and two equivalent Hf(1) atoms. In the fifth F site, F(3) is bonded in a 3-coordinate geometry to one K(1), one Hf(1), and one Cu(1) atom. In the sixth F site, F(4) is bonded in a distorted water-like geometry to two equivalent K(1), one Hf(1), and one Cu(1) atom. In the seventh F site, F(5) is bonded to two equivalent K(1) and two equivalent Hf(1) atoms to form distorted FK2Hf2 tetrahedra that share corners with six equivalent F(1)K2HfCu tetrahedra and edges with two equivalent F(5)K2Hf2 tetrahedra.
KHfCuF7 crystallizes in the orthorhombic Cmcm space group. K(1) is bonded in a 10-coordinate geometry to one F(2), one F(6), two equivalent F(1), two equivalent F(3), two equivalent F(4), and two equivalent F(5) atoms. The K(1)-F(2) bond length is 3.14 Å. The K(1)-F(6) bond length is 2.98 Å. Both K(1)-F(1) bond lengths are 2.76 Å. Both K(1)-F(3) bond lengths are 2.68 Å. Both K(1)-F(4) bond lengths are 2.98 Å. Both K(1)-F(5) bond lengths are 2.73 Å. Hf(1) is bonded in a 8-coordinate geometry to one F(1), one F(4), two equivalent F(2), two equivalent F(3), and two equivalent F(5) atoms. The Hf(1)-F(1) bond length is 2.06 Å. The Hf(1)-F(4) bond length is 2.15 Å. Both Hf(1)-F(2) bond lengths are 2.14 Å. Both Hf(1)-F(3) bond lengths are 1.99 Å. There is one shorter (2.06 Å) and one longer (2.28 Å) Hf(1)-F(5) bond length. Cu(1) is bonded to one F(1), one F(4), one F(6), one F(7), and two equivalent F(3) atoms to form distorted corner-sharing CuF6 octahedra. The corner-sharing octahedral tilt angles range from 0-45°. The Cu(1)-F(1) bond length is 2.04 Å. The Cu(1)-F(4) bond length is 1.87 Å. The Cu(1)-F(6) bond length is 1.93 Å. The Cu(1)-F(7) bond length is 1.86 Å. Both Cu(1)-F(3) bond lengths are 2.29 Å. There are seven inequivalent F sites. In the first F site, F(6) is bonded in a 2-coordinate geometry to two equivalent K(1) and two equivalent Cu(1) atoms. In the second F site, F(7) is bonded in a linear geometry to two equivalent Cu(1) atoms. In the third F site, F(1) is bonded to two equivalent K(1), one Hf(1), and one Cu(1) atom to form distorted FK2HfCu tetrahedra that share corners with six equivalent F(5)K2Hf2 tetrahedra and  an edgeedge with one F(1)K2HfCu tetrahedra. In the fourth F site, F(2) is bonded in a distorted bent 120 degrees geometry to one K(1) and two equivalent Hf(1) atoms. In the fifth F site, F(3) is bonded in a 3-coordinate geometry to one K(1), one Hf(1), and one Cu(1) atom. In the sixth F site, F(4) is bonded in a distorted water-like geometry to two equivalent K(1), one Hf(1), and one Cu(1) atom. In the seventh F site, F(5) is bonded to two equivalent K(1) and two equivalent Hf(1) atoms to form distorted FK2Hf2 tetrahedra that share corners with six equivalent F(1)K2HfCu tetrahedra and edges with two equivalent F(5)K2Hf2 tetrahedra.