DOI: 10.17188/1717165
title: Materials Data on HfCo7 by Materials Project

description: Co7Hf crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. there are two inequivalent Hf sites. In the first Hf site, Hf is bonded to twelve Co atoms to form HfCo12 cuboctahedra that share corners with four equivalent HfCo12 cuboctahedra, corners with eight CoCo12 cuboctahedra, edges with sixteen CoHf2Co10 cuboctahedra, faces with two equivalent HfCo12 cuboctahedra, and faces with sixteen CoCo12 cuboctahedra. There are a spread of Hf–Co bond distances ranging from 2.60–2.66 Å. In the second Hf site, Hf is bonded to twelve Co atoms to form HfCo12 cuboctahedra that share corners with four equivalent HfCo12 cuboctahedra, corners with eight CoCo12 cuboctahedra, edges with twenty-four CoHf2Co10 cuboctahedra, faces with two equivalent HfCo12 cuboctahedra, and faces with twelve CoCo12 cuboctahedra. There are a spread of Hf–Co bond distances ranging from 2.60–2.67 Å. There are seven inequivalent Co sites. In the first Co site, Co is bonded to twelve Co atoms to form CoCo12 cuboctahedra that share corners with four equivalent CoCo12 cuboctahedra, corners with eight HfCo12 cuboctahedra, edges with sixteen CoHf2Co10 cuboctahedra, faces with four HfCo12 cuboctahedra, and faces with fourteen CoCo12 cuboctahedra. There are eight shorter (2.46 Å) and four longer (2.59 Å) Co–Co bond lengths. In the second Co site, Co is bonded to two equivalent Hf and ten Co atoms to form distorted CoHf2Co10 cuboctahedra that share corners with four equivalent CoHf2Co10 cuboctahedra, edges with four equivalent HfCo12 cuboctahedra, edges with twenty CoHf2Co10 cuboctahedra, faces with two equivalent HfCo12 cuboctahedra, and faces with fourteen CoCo12 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.40–2.78 Å. In the third Co site, Co is bonded to two equivalent Hf and ten Co atoms to form distorted CoHf2Co10 cuboctahedra that share corners with twelve CoHf2Co10 cuboctahedra, edges with four equivalent HfCo12 cuboctahedra, edges with sixteen CoHf2Co10 cuboctahedra, faces with two equivalent HfCo12 cuboctahedra, and faces with fourteen CoCo12 cuboctahedra. There are four shorter (2.56 Å) and two longer (2.79 Å) Co–Co bond lengths. In the fourth Co site, Co is bonded to two equivalent Hf and ten Co atoms to form distorted CoHf2Co10 cuboctahedra that share corners with twelve CoHf2Co10 cuboctahedra, edges with four equivalent HfCo12 cuboctahedra, edges with sixteen CoCo12 cuboctahedra, faces with two equivalent HfCo12 cuboctahedra, and faces with fourteen CoHf2Co10 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.42–2.56 Å. In the fifth Co site, Co is bonded to two Hf and ten Co atoms to form distorted CoHf2Co10 cuboctahedra that share corners with twelve equivalent CoHf2Co10 cuboctahedra, edges with four HfCo12 cuboctahedra, edges with sixteen CoCo12 cuboctahedra, faces with two HfCo12 cuboctahedra, and faces with fourteen CoCo12 cuboctahedra. There are two shorter (2.57 Å) and one longer (2.60 Å) Co–Co bond lengths. In the sixth Co site, Co is bonded to twelve Co atoms to form CoCo12 cuboctahedra that share corners with four equivalent CoCo12 cuboctahedra, corners with eight HfCo12 cuboctahedra, edges with twenty-four CoHf2Co10 cuboctahedra, faces with four HfCo12 cuboctahedra, and faces with ten CoHf2Co10 cuboctahedra. All Co–Co bond lengths are 2.47 Å. In the seventh Co site, Co is bonded in a 12-coordinate geometry to two equivalent Hf and ten Co atoms.