Materials Data on Nb3B4 by Materials Project
Nb3B4 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. there are two inequivalent Nb2+ sites. In the first Nb2+ site, Nb2+ is bonded to twelve B+1.50- atoms to form a mixture of edge and face-sharing NbB12 cuboctahedra. There are eight shorter (2.47 Å) and four longer (2.51 Å) Nb–B bond lengths. In the second Nb2+ site, Nb2+ is bonded in a 7-coordinate geometry to seven B+1.50- atoms. There are a spread of Nb–B bond distances ranging from 2.39–2.59 Å. There are two inequivalent B+1.50- sites. In the first B+1.50- site, B+1.50- is bonded in a 9-coordinate geometry to seven Nb2+ and two equivalent B+1.50- atoms. Both B–B bond lengths are 1.85 Å. In the second B+1.50- site, B+1.50- is bonded in a 9-coordinate geometry to six Nb2+ and three B+1.50- atoms. The B–B bond length is 1.82 Å.