DOE OSTI2020
HfZn16 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Hf is bonded in a 9-coordinate geometry to fifteen Zn atoms. There are a spread of Hf–Zn bond distances ranging from 2.83–3.01 Å. There are seven inequivalent Zn sites. In the first Zn site, Zn is bonded in a 1-coordinate geometry to one Hf and ten Zn atoms. There are a spread of Zn–Zn bond distances ranging from 2.74–3.13 Å. In the second Zn site, Zn is bonded to two equivalent Hf and ten Zn atoms to form ZnHf2Zn10 cuboctahedra that share corners with two equivalent ZnHf2Zn10 cuboctahedra and faces with six equivalent ZnZn12 cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.64–2.87 Å. In the third Zn site, Zn is bonded in a 9-coordinate geometry to one Hf and twelve Zn atoms. There are a spread of Zn–Zn bond distances ranging from 2.54–3.12 Å. In the fourth Zn site, Zn is bonded in a 12-coordinate geometry to one Hf and eleven Zn atoms. There are a spread of Zn–Zn bond distances ranging from 2.62–3.14 Å. In the fifth Zn site, Zn is bonded in a 11-coordinate geometry to one Hf and ten Zn atoms. There are a spread of Zn–Zn bond distances ranging from 2.53–2.90 Å. In the sixth Zn site, Zn is bonded in a 12-coordinate geometry to one Hf and eleven Zn atoms. There are one shorter (2.62 Å) and one longer (2.66 Å) Zn–Zn bond lengths. In the seventh Zn site, Zn is bonded to twelve Zn atoms to form distorted ZnZn12 cuboctahedra that share edges with three equivalent ZnZn12 cuboctahedra and faces with four ZnHf2Zn10 cuboctahedra. The Zn–Zn bond length is 2.89 Å.