DOE OSTI2020
V2MoCo9 is beta Cu3Ti-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are two inequivalent V sites. In the first V site, V is bonded to twelve Co atoms to form VCo12 cuboctahedra that share corners with three equivalent MoCo12 cuboctahedra, corners with six equivalent VCo12 cuboctahedra, corners with six CoV3Co8Mo cuboctahedra, edges with twenty-one CoV3Co8Mo cuboctahedra, faces with three equivalent MoCo12 cuboctahedra, faces with four equivalent VCo12 cuboctahedra, and faces with twelve CoV3Co8Mo cuboctahedra. There are a spread of V–Co bond distances ranging from 2.47–2.53 Å. In the second V site, V is bonded to twelve Co atoms to form VCo12 cuboctahedra that share corners with six equivalent VCo12 cuboctahedra, corners with twelve CoV3Co8Mo cuboctahedra, edges with eighteen CoV3Co8Mo cuboctahedra, faces with four equivalent VCo12 cuboctahedra, faces with four equivalent MoCo12 cuboctahedra, and faces with twelve CoV3Co8Mo cuboctahedra. There are six shorter (2.51 Å) and six longer (2.52 Å) V–Co bond lengths. Mo is bonded to twelve Co atoms to form MoCo12 cuboctahedra that share corners with three equivalent VCo12 cuboctahedra, corners with six equivalent MoCo12 cuboctahedra, corners with six equivalent CoV3Co8Mo cuboctahedra, edges with twenty-one CoV3Co8Mo cuboctahedra, faces with seven VCo12 cuboctahedra, and faces with twelve CoV3Co8Mo cuboctahedra. There are a spread of Mo–Co bond distances ranging from 2.50–2.56 Å. There are seven inequivalent Co sites. In the first Co site, Co is bonded to three V, one Mo, and eight Co atoms to form distorted CoV3Co8Mo cuboctahedra that share corners with two equivalent VCo12 cuboctahedra, corners with thirteen CoV3Co8Mo cuboctahedra, edges with three equivalent MoCo12 cuboctahedra, edges with four VCo12 cuboctahedra, edges with fourteen CoV3Co8Mo cuboctahedra, a faceface with one MoCo12 cuboctahedra, faces with three VCo12 cuboctahedra, and faces with fifteen CoV3Co8Mo cuboctahedra. The Co–V bond length is 2.51 Å. There are a spread of Co–Co bond distances ranging from 2.44–2.60 Å. In the second Co site, Co is bonded to three V, one Mo, and eight Co atoms to form distorted CoV3Co8Mo cuboctahedra that share corners with two equivalent VCo12 cuboctahedra, corners with thirteen CoV3Co8Mo cuboctahedra, edges with three equivalent MoCo12 cuboctahedra, edges with four VCo12 cuboctahedra, edges with fourteen CoV3Co8Mo cuboctahedra, a faceface with one MoCo12 cuboctahedra, faces with three VCo12 cuboctahedra, and faces with fifteen CoV3Co8Mo cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.44–2.60 Å. In the third Co site, Co is bonded to three V, one Mo, and eight Co atoms to form distorted CoV3Co8Mo cuboctahedra that share corners with two equivalent VCo12 cuboctahedra, corners with thirteen CoV3Co8Mo cuboctahedra, edges with three equivalent MoCo12 cuboctahedra, edges with four VCo12 cuboctahedra, edges with fourteen CoV3Co8Mo cuboctahedra, a faceface with one MoCo12 cuboctahedra, faces with three VCo12 cuboctahedra, and faces with fifteen CoV3Co8Mo cuboctahedra. There are two shorter (2.46 Å) and two longer (2.50 Å) Co–Co bond lengths. In the fourth Co site, Co is bonded to two V, two equivalent Mo, and eight Co atoms to form distorted CoV2Co8Mo2 cuboctahedra that share corners with two equivalent VCo12 cuboctahedra, corners with thirteen CoV3Co8Mo cuboctahedra, edges with two equivalent MoCo12 cuboctahedra, edges with five VCo12 cuboctahedra, edges with fourteen CoV3Co8Mo cuboctahedra, faces with two VCo12 cuboctahedra, faces with two equivalent MoCo12 cuboctahedra, and faces with fifteen CoV3Co8Mo cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.45–2.58 Å. In the fifth Co site, Co is bonded to three V, one Mo, and eight Co atoms to form CoV3Co8Mo cuboctahedra that share corners with two equivalent VCo12 cuboctahedra, corners with two equivalent MoCo12 cuboctahedra, corners with fourteen CoV3Co8Mo cuboctahedra, edges with two equivalent MoCo12 cuboctahedra, edges with four VCo12 cuboctahedra, edges with twelve CoV3Co8Mo cuboctahedra, a faceface with one MoCo12 cuboctahedra, faces with three VCo12 cuboctahedra, and faces with sixteen CoV3Co8Mo cuboctahedra. There are three shorter (2.49 Å) and two longer (2.54 Å) Co–Co bond lengths. In the sixth Co site, Co is bonded to two V, two equivalent Mo, and eight Co atoms to form distorted CoV2Co8Mo2 cuboctahedra that share corners with two equivalent VCo12 cuboctahedra, corners with thirteen CoV3Co8Mo cuboctahedra, edges with two equivalent MoCo12 cuboctahedra, edges with five VCo12 cuboctahedra, edges with fourteen CoV3Co8Mo cuboctahedra, faces with two VCo12 cuboctahedra, faces with two equivalent MoCo12 cuboctahedra, and faces with fifteen CoV3Co8Mo cuboctahedra. There are one shorter (2.47 Å) and one longer (2.51 Å) Co–V bond lengths. Both Co–Mo bond lengths are 2.52 Å. There are a spread of Co–Co bond distances ranging from 2.45–2.58 Å. In the seventh Co site, Co is bonded to three V, one Mo, and eight Co atoms to form CoV3Co8Mo cuboctahedra that share corners with two equivalent VCo12 cuboctahedra, corners with two equivalent MoCo12 cuboctahedra, corners with fourteen CoV3Co8Mo cuboctahedra, edges with two equivalent MoCo12 cuboctahedra, edges with four VCo12 cuboctahedra, edges with twelve CoV3Co8Mo cuboctahedra, a faceface with one MoCo12 cuboctahedra, faces with three VCo12 cuboctahedra, and faces with sixteen CoV3Co8Mo cuboctahedra. The Co–V bond length is 2.53 Å. There are a spread of Co–Co bond distances ranging from 2.46–2.54 Å.