K2MgCuF6 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal P4/mmm space group. K(1) is bonded to four equivalent F(1), four equivalent F(2), and four equivalent F(3) atoms to form KF12 cuboctahedra that share corners with twelve equivalent K(1)F12 cuboctahedra, faces with six equivalent K(1)F12 cuboctahedra, faces with four equivalent Mg(1)F6 octahedra, and faces with four equivalent Cu(1)F6 octahedra. Mg(1) is bonded to two equivalent F(1) and four equivalent F(3) atoms to form MgF6 octahedra that share corners with two equivalent Cu(1)F6 octahedra, corners with four equivalent Mg(1)F6 octahedra, and faces with eight equivalent K(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. Cu(1) is bonded to two equivalent F(1) and four equivalent F(2) atoms to form CuF6 octahedra that share corners with two equivalent Mg(1)F6 octahedra, corners with four equivalent Cu(1)F6 octahedra, and faces with eight equivalent K(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. There are three inequivalent F sites. In the first F site, F(1) is bonded in a distorted linear geometry to four equivalent K(1), one Mg(1), and one Cu(1) atom. In the second F site, F(2) is bonded to four equivalent K(1) and two equivalent Cu(1) atoms to form a mixture of distorted corner, edge, and face-sharing FK4Cu2 octahedra. The corner-sharing octahedra are not tilted. In the third F site, F(3) is bonded in a distorted linear geometry to four equivalent K(1) and two equivalent Mg(1) atoms.
K2MgCuF6 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal P4/mmm space group. K(1) is bonded to four equivalent F(1), four equivalent F(2), and four equivalent F(3) atoms to form KF12 cuboctahedra that share corners with twelve equivalent K(1)F12 cuboctahedra, faces with six equivalent K(1)F12 cuboctahedra, faces with four equivalent Mg(1)F6 octahedra, and faces with four equivalent Cu(1)F6 octahedra. All K(1)-F(1) bond lengths are 2.88 Å. All K(1)-F(2) bond lengths are 2.87 Å. All K(1)-F(3) bond lengths are 2.88 Å. Mg(1) is bonded to two equivalent F(1) and four equivalent F(3) atoms to form MgF6 octahedra that share corners with two equivalent Cu(1)F6 octahedra, corners with four equivalent Mg(1)F6 octahedra, and faces with eight equivalent K(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. Both Mg(1)-F(1) bond lengths are 2.02 Å. All Mg(1)-F(3) bond lengths are 2.03 Å. Cu(1) is bonded to two equivalent F(1) and four equivalent F(2) atoms to form CuF6 octahedra that share corners with two equivalent Mg(1)F6 octahedra, corners with four equivalent Cu(1)F6 octahedra, and faces with eight equivalent K(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. Both Cu(1)-F(1) bond lengths are 2.04 Å. All Cu(1)-F(2) bond lengths are 2.03 Å. There are three inequivalent F sites. In the first F site, F(1) is bonded in a distorted linear geometry to four equivalent K(1), one Mg(1), and one Cu(1) atom. In the second F site, F(2) is bonded to four equivalent K(1) and two equivalent Cu(1) atoms to form a mixture of distorted corner, edge, and face-sharing FK4Cu2 octahedra. The corner-sharing octahedra are not tilted. In the third F site, F(3) is bonded in a distorted linear geometry to four equivalent K(1) and two equivalent Mg(1) atoms.