Materials Data on Co6W20C7 by Materials Project

Abstract

C7Co6W20 crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. there are five inequivalent W sites. In the first W site, W is bonded in a 3-coordinate geometry to three Co and three C atoms. There are two shorter (2.79 Å) and one longer (2.84 Å) W–Co bond lengths. There are two shorter (2.17 Å) and one longer (2.26 Å) W–C bond lengths. In the second W site, W is bonded in a 2-coordinate geometry to three Co and two equivalent C atoms. There are two shorter (2.75 Å) and one longer (2.80 Å) W–Co bond lengths. Both W–C bond lengths are 2.14 Å. In the third W site, W is bonded in a distorted rectangular see-saw-like geometry to two equivalent Co and two equivalent C atoms. Both W–Co bond lengths are 2.62 Å. Both W–C bond lengths are 2.08 Å. In the fourth W site, W is bonded in a distorted rectangular see-saw-like geometry to two equivalent Co and two equivalent C atoms. Both W–Co bond lengths are 2.63 Å. Both W–C bond lengths are 2.09 Å. In the fifth W site, W is bonded in a 6-coordinate geometry to six Co atoms. There are three shorter (2.48 Å) and three longer (2.49 Å) W–Co bond lengths. There are two inequivalent Co sites. In the first Co site, Co is bonded to ten W and two equivalent Co atoms to form distorted CoCo2W10 cuboctahedra that share corners with two equivalent CoCo2W10 cuboctahedra, corners with four equivalent CW6 octahedra, faces with two equivalent CoCo2W10 cuboctahedra, and faces with four equivalent CW6 octahedra. The corner-sharing octahedral tilt angles are 39°. Both Co–Co bond lengths are 2.63 Å. In the second Co site, Co is bonded in a 12-coordinate geometry to ten W and two equivalent Co atoms. Both Co–Co bond lengths are 2.62 Å. There are two inequivalent C sites. In the first C site, C is bonded in a 6-coordinate geometry to six equivalent W atoms. In the second C site, C is bonded to six W atoms to form CW6 octahedra that share corners with two equivalent CoCo2W10 cuboctahedra, corners with six equivalent CW6 octahedra, and faces with two equivalent CoCo2W10 cuboctahedra. The corner-sharing octahedra tilt angles range from 38–50°.