K2CuF4 is (La,Ba)CuO4-like structured and crystallizes in the orthorhombic Cmce space group. K(1) is bonded in a 9-coordinate geometry to four equivalent F(1) and five equivalent F(2) atoms. Cu(1) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form corner-sharing CuF6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent F sites. In the first F site, F(1) is bonded to four equivalent K(1) and two equivalent Cu(1) atoms to form distorted FK4Cu2 octahedra that share corners with two equivalent F(1)K4Cu2 octahedra, corners with twelve equivalent F(2)K5Cu octahedra, edges with two equivalent F(1)K4Cu2 octahedra, faces with four equivalent F(1)K4Cu2 octahedra, and faces with four equivalent F(2)K5Cu octahedra. The corner-sharing octahedral tilt angles range from 0-58°. In the second F site, F(2) is bonded to five equivalent K(1) and one Cu(1) atom to form distorted FK5Cu octahedra that share corners with five equivalent F(2)K5Cu octahedra, corners with twelve equivalent F(1)K4Cu2 octahedra, edges with eight equivalent F(2)K5Cu octahedra, and faces with four equivalent F(1)K4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-58°.
K2CuF4 is (La,Ba)CuO4-like structured and crystallizes in the orthorhombic Cmce space group. K(1) is bonded in a 9-coordinate geometry to four equivalent F(1) and five equivalent F(2) atoms. All K(1)-F(1) bond lengths are 2.74 Å. There is one shorter (2.60 Å) and four longer (2.91 Å) K(1)-F(2) bond lengths. Cu(1) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form corner-sharing CuF6 octahedra. The corner-sharing octahedra are not tilted. Both Cu(1)-F(2) bond lengths are 1.95 Å. There are two shorter (1.90 Å) and two longer (2.20 Å) Cu(1)-F(1) bond lengths. There are two inequivalent F sites. In the first F site, F(1) is bonded to four equivalent K(1) and two equivalent Cu(1) atoms to form distorted FK4Cu2 octahedra that share corners with two equivalent F(1)K4Cu2 octahedra, corners with twelve equivalent F(2)K5Cu octahedra, edges with two equivalent F(1)K4Cu2 octahedra, faces with four equivalent F(1)K4Cu2 octahedra, and faces with four equivalent F(2)K5Cu octahedra. The corner-sharing octahedral tilt angles range from 0-58°. In the second F site, F(2) is bonded to five equivalent K(1) and one Cu(1) atom to form distorted FK5Cu octahedra that share corners with five equivalent F(2)K5Cu octahedra, corners with twelve equivalent F(1)K4Cu2 octahedra, edges with eight equivalent F(2)K5Cu octahedra, and faces with four equivalent F(1)K4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-58°.