DOE OSTI2020
Rb3Au7 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded to twelve Au+0.43- atoms to form RbAu12 cuboctahedra that share corners with four equivalent RbAu12 cuboctahedra, faces with two equivalent RbAu12 cuboctahedra, and faces with eight equivalent AuRb6Au6 cuboctahedra. There are eight shorter (3.45 Å) and four longer (3.79 Å) Rb–Au bond lengths. In the second Rb1+ site, Rb1+ is bonded in a 6-coordinate geometry to two equivalent Rb1+ and twelve Au+0.43- atoms. Both Rb–Rb bond lengths are 3.78 Å. There are a spread of Rb–Au bond distances ranging from 3.56–4.15 Å. There are three inequivalent Au+0.43- sites. In the first Au+0.43- site, Au+0.43- is bonded in a body-centered cubic geometry to four equivalent Rb1+ and four equivalent Au+0.43- atoms. All Au–Au bond lengths are 2.70 Å. In the second Au+0.43- site, Au+0.43- is bonded to six Rb1+ and six Au+0.43- atoms to form distorted AuRb6Au6 cuboctahedra that share corners with ten equivalent AuRb6Au6 cuboctahedra, edges with two equivalent AuRb6Au6 cuboctahedra, faces with two equivalent AuRb6Au6 cuboctahedra, and faces with four equivalent RbAu12 cuboctahedra. There are two shorter (2.77 Å) and four longer (2.86 Å) Au–Au bond lengths. In the third Au+0.43- site, Au+0.43- is bonded in a 10-coordinate geometry to five Rb1+ and five Au+0.43- atoms. There are one shorter (2.87 Å) and one longer (2.96 Å) Au–Au bond lengths.