Materials Data on HfGeB2 by Materials Project
HfB2Ge crystallizes in the cubic F-43m space group. The structure is three-dimensional. Hf4+ is bonded to ten B3- atoms to form distorted HfB10 tetrahedra that share corners with six equivalent HfB10 tetrahedra, corners with twelve equivalent GeB4 tetrahedra, faces with four equivalent GeB4 tetrahedra, and faces with twelve equivalent HfB10 tetrahedra. There are four shorter (2.62 Å) and six longer (3.02 Å) Hf–B bond lengths. There are two inequivalent B3- sites. In the first B3- site, B3- is bonded to four equivalent Hf4+ atoms to form corner-sharing BHf4 tetrahedra. In the second B3- site, B3- is bonded in a 10-coordinate geometry to six equivalent Hf4+ and four equivalent Ge2+ atoms. All B–Ge bond lengths are 2.62 Å. Ge2+ is bonded to four equivalent B3- atoms to form distorted GeB4 tetrahedra that share corners with twelve equivalent HfB10 tetrahedra, corners with twelve equivalent GeB4 tetrahedra, and faces with four equivalent HfB10 tetrahedra.