DOE OSTI2020
HfZrRhCoSb2 is half-Heusler-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. Hf is bonded in a body-centered cubic geometry to three equivalent Rh, one Co, and four Sb atoms. All Hf–Rh bond lengths are 2.80 Å. The Hf–Co bond length is 2.79 Å. There are three shorter (2.80 Å) and one longer (2.82 Å) Hf–Sb bond lengths. Zr is bonded in a body-centered cubic geometry to one Rh, three equivalent Co, and four Sb atoms. The Zr–Rh bond length is 2.83 Å. All Zr–Co bond lengths are 2.80 Å. There are one shorter (2.80 Å) and three longer (2.81 Å) Zr–Sb bond lengths. Rh is bonded to three equivalent Hf and one Zr atom to form distorted RhHf3Zr tetrahedra that share corners with four equivalent SbHf3Zr tetrahedra, corners with six equivalent RhHf3Zr tetrahedra, corners with six equivalent CoHfZr3 tetrahedra, and edges with six SbHf3Zr tetrahedra. Co is bonded to one Hf and three equivalent Zr atoms to form distorted CoHfZr3 tetrahedra that share corners with four equivalent SbHfZr3 tetrahedra, corners with six equivalent RhHf3Zr tetrahedra, corners with six equivalent CoHfZr3 tetrahedra, and edges with six SbHf3Zr tetrahedra. There are two inequivalent Sb sites. In the first Sb site, Sb is bonded to three equivalent Hf and one Zr atom to form distorted SbHf3Zr tetrahedra that share corners with four equivalent RhHf3Zr tetrahedra, corners with twelve SbHf3Zr tetrahedra, edges with three equivalent RhHf3Zr tetrahedra, and edges with three equivalent CoHfZr3 tetrahedra. In the second Sb site, Sb is bonded to one Hf and three equivalent Zr atoms to form distorted SbHfZr3 tetrahedra that share corners with four equivalent CoHfZr3 tetrahedra, corners with twelve SbHf3Zr tetrahedra, edges with three equivalent RhHf3Zr tetrahedra, and edges with three equivalent CoHfZr3 tetrahedra.