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Materials Data on As2Ir by Materials Project

IrAs2 is Spinel-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ir5+ is bonded to six As+2.50- atoms to form IrAs6 octahedra that share corners with eight equivalent IrAs6 octahedra, corners with six AsAsIr3 tetrahedra, and edges with two equivalent IrAs6 octahedra. The corner-sharing octahedra tilt angles range from 54–60°. There are a spread of Ir–As bond distances ranging from 2.45–2.54 Å. There are two inequivalent As+2.50- sites. In the first As+2.50- site, As+2.50- is bonded to three equivalent Ir5+ and one As+2.50- atom to form AsAsIr3 tetrahedra that share corners with three equivalent IrAs6 octahedra, corners with thirteen AsAsIr3 tetrahedra, and an edgeedge with one AsAsIr3 tetrahedra. The corner-sharing octahedra tilt angles range from 68–72°. The As–As bond length is 2.50 Å. In the second As+2.50- site, As+2.50- is bonded to three equivalent Ir5+ and one As+2.50- atom to form AsAsIr3 tetrahedra that share corners with three equivalent IrAs6 octahedra, corners with thirteen AsAsIr3 tetrahedra, and an edgeedge with one AsAsIr3 tetrahedra. The corner-sharing octahedra tilt angles range from 73–79°.

36 MATERIALS SCIENCE↗

Materials Data on As3Ir by Materials Project

IrAs3 is Skutterudite structured and crystallizes in the cubic Im-3 space group. The structure is three-dimensional. Ir3+ is bonded to six equivalent As1- atoms to form IrAs6 octahedra that share corners with six equivalent IrAs6 octahedra and corners with twelve equivalent AsAs2Ir2 tetrahedra. The corner-sharing octahedral tilt angles are 60°. All Ir–As bond lengths are 2.48 Å. As1- is bonded to two equivalent Ir3+ and two equivalent As1- atoms to form AsAs2Ir2 tetrahedra that share corners with four equivalent IrAs6 octahedra, corners with ten equivalent AsAs2Ir2 tetrahedra, and an edgeedge with one AsAs2Ir2 tetrahedra. The corner-sharing octahedra tilt angles range from 69–70°. There are one shorter (2.51 Å) and one longer (2.62 Å) As–As bond lengths.

36 MATERIALS SCIENCE↗