DOE OSTI2020
W2CO is Tungsten Carbide-derived structured and crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. there are two inequivalent W3+ sites. In the first W3+ site, W3+ is bonded in a 6-coordinate geometry to four equivalent C4- and two equivalent O2- atoms. All W–C bond lengths are 2.27 Å. Both W–O bond lengths are 2.34 Å. In the second W3+ site, W3+ is bonded to two equivalent C4- and four equivalent O2- atoms to form a mixture of distorted corner, edge, and face-sharing WC2O4 pentagonal pyramids. Both W–C bond lengths are 2.23 Å. All W–O bond lengths are 2.33 Å. C4- is bonded to six W3+ atoms to form distorted CW6 pentagonal pyramids that share corners with four equivalent CW6 pentagonal pyramids, corners with eight equivalent OW6 pentagonal pyramids, edges with two equivalent CW6 pentagonal pyramids, edges with four equivalent OW6 pentagonal pyramids, and faces with two equivalent CW6 pentagonal pyramids. O2- is bonded to six W3+ atoms to form distorted OW6 pentagonal pyramids that share corners with four equivalent OW6 pentagonal pyramids, corners with eight equivalent CW6 pentagonal pyramids, edges with two equivalent OW6 pentagonal pyramids, edges with four equivalent CW6 pentagonal pyramids, and faces with two equivalent OW6 pentagonal pyramids.