DOE OSTI2020
HfCr2 is Hexagonal Laves-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are five inequivalent Hf sites. In the first Hf site, Hf is bonded in a 12-coordinate geometry to four Hf and twelve Cr atoms. All Hf–Hf bond lengths are 3.08 Å. There are three shorter (2.91 Å) and nine longer (2.95 Å) Hf–Cr bond lengths. In the second Hf site, Hf is bonded in a 12-coordinate geometry to four Hf and twelve Cr atoms. All Hf–Hf bond lengths are 3.08 Å. There are three shorter (2.91 Å) and nine longer (2.95 Å) Hf–Cr bond lengths. In the third Hf site, Hf is bonded in a 12-coordinate geometry to four Hf and twelve Cr atoms. There are one shorter (3.06 Å) and three longer (3.08 Å) Hf–Hf bond lengths. There are a spread of Hf–Cr bond distances ranging from 2.93–2.96 Å. In the fourth Hf site, Hf is bonded in a 12-coordinate geometry to four Hf and twelve Cr atoms. There are one shorter (3.06 Å) and three longer (3.08 Å) Hf–Hf bond lengths. There are a spread of Hf–Cr bond distances ranging from 2.93–2.96 Å. In the fifth Hf site, Hf is bonded in a 12-coordinate geometry to four Hf and twelve Cr atoms. There are a spread of Hf–Cr bond distances ranging from 2.93–2.96 Å. There are three inequivalent Cr sites. In the first Cr site, Cr is bonded to six Hf and six Cr atoms to form a mixture of edge, face, and corner-sharing CrHf6Cr6 cuboctahedra. There are two shorter (2.48 Å) and four longer (2.52 Å) Cr–Cr bond lengths. In the second Cr site, Cr is bonded to six Hf and six Cr atoms to form a mixture of edge, face, and corner-sharing CrHf6Cr6 cuboctahedra. All Cr–Cr bond lengths are 2.54 Å. In the third Cr site, Cr is bonded to six Hf and six Cr atoms to form a mixture of edge, face, and corner-sharing CrHf6Cr6 cuboctahedra. There are two shorter (2.48 Å) and two longer (2.55 Å) Cr–Cr bond lengths.