DOE OSTI2020
K3Ru is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to four equivalent K and four equivalent Ru atoms to form distorted KK4Ru4 tetrahedra that share corners with eight equivalent KK8Ru4 cuboctahedra, corners with eight equivalent KK4Ru4 tetrahedra, edges with four equivalent KK8Ru4 cuboctahedra, edges with twelve equivalent KK4Ru4 tetrahedra, and faces with six equivalent KK4Ru4 tetrahedra. All K–K bond lengths are 3.69 Å. All K–Ru bond lengths are 3.69 Å. In the second K site, K is bonded to eight equivalent K and four equivalent Ru atoms to form KK8Ru4 cuboctahedra that share corners with four equivalent KK8Ru4 cuboctahedra, corners with sixteen equivalent KK4Ru4 tetrahedra, edges with eight equivalent KK8Ru4 cuboctahedra, edges with eight equivalent KK4Ru4 tetrahedra, and faces with four equivalent KK8Ru4 cuboctahedra. All K–Ru bond lengths are 4.18 Å. Ru is bonded in a body-centered cubic geometry to twelve K atoms.