Materials Data on HfAlIr by Materials Project

HfIrAl crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent Hf sites. In the first Hf site, Hf is bonded in a 12-coordinate geometry to three equivalent Hf, five Ir, and four equivalent Al atoms. There are two shorter (3.21 Å) and one longer (3.23 Å) Hf–Hf bond lengths. There are a spread of Hf–Ir bond distances ranging from 2.83–3.19 Å. There are two shorter (3.16 Å) and two longer (3.18 Å) Hf–Al bond lengths. In the second Hf site, Hf is bonded in a 7-coordinate geometry to four Hf, seven Ir, and five Al atoms. The Hf–Hf bond length is 2.94 Å. There are a spread of Hf–Ir bond distances ranging from 3.01–3.07 Å. There are a spread of Hf–Al bond distances ranging from 3.03–3.18 Å. There are three inequivalent Ir sites. In the first Ir site, Ir is bonded to six Hf and six Al atoms to form distorted IrHf6Al6 cuboctahedra that share corners with six IrHf6Al6 cuboctahedra and edges with six IrHf6Al2Ir4 cuboctahedra. There are a spread of Ir–Al bond distances ranging from 2.58–2.74 Å. In the second Ir site, Ir is bonded in a 12-coordinate geometry to six Hf, four Ir, and two equivalent Al atoms. There are a spread of Ir–Ir bond distances ranging from 2.64–2.72 Å. Both Ir–Al bond lengths are 2.54 Å. In the third Ir site, Ir is bonded to six Hf, four equivalent Ir, and two equivalent Al atoms to form distorted IrHf6Al2Ir4 cuboctahedra that share corners with six IrHf6Al6 cuboctahedra and edges with six IrHf6Al2Ir4 cuboctahedra. Both Ir–Al bond lengths are 2.57 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to three equivalent Hf, four Ir, and two equivalent Al atoms. Both Al–Al bond lengths are 2.65 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to six Hf, two equivalent Ir, and four Al atoms. There are one shorter (2.59 Å) and one longer (2.77 Å) Al–Al bond lengths.