Materials Data on Ba4(NbSe4)3 by Materials Project

Ba4(NbSe4)3 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve Se+1.92- atoms to form BaSe12 cuboctahedra that share corners with six BaSe12 cuboctahedra, corners with five NbSe6 octahedra, faces with eight BaSe12 cuboctahedra, and faces with four NbSe6 octahedra. The corner-sharing octahedra tilt angles range from 14–30°. There are a spread of Ba–Se bond distances ranging from 3.49–3.72 Å. In the second Ba2+ site, Ba2+ is bonded to twelve Se+1.92- atoms to form BaSe12 cuboctahedra that share corners with six BaSe12 cuboctahedra, corners with four NbSe6 octahedra, faces with eight BaSe12 cuboctahedra, and faces with five NbSe6 octahedra. The corner-sharing octahedra tilt angles range from 16–31°. There are a spread of Ba–Se bond distances ranging from 3.49–3.74 Å. There are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six Se+1.92- atoms to form NbSe6 octahedra that share corners with six BaSe12 cuboctahedra, faces with six BaSe12 cuboctahedra, and faces with two equivalent NbSe6 octahedra. All Nb–Se bond lengths are 2.60 Å. In the second Nb5+ site, Nb5+ is bonded to six Se+1.92- atoms to form distorted NbSe6 octahedra that share corners with six BaSe12 cuboctahedra, faces with six BaSe12 cuboctahedra, and a faceface with one NbSe6 octahedra. There are a spread of Nb–Se bond distances ranging from 2.45–2.80 Å. There are six inequivalent Se+1.92- sites. In the first Se+1.92- site, Se+1.92- is bonded in a 6-coordinate geometry to four Ba2+ and two Nb5+ atoms. In the second Se+1.92- site, Se+1.92- is bonded in a distorted single-bond geometry to four Ba2+ and one Nb5+ atom. In the third Se+1.92- site, Se+1.92- is bonded in a distorted single-bond geometry to four Ba2+ and one Nb5+ atom. In the fourth Se+1.92- site, Se+1.92- is bonded in a 2-coordinate geometry to four Ba2+ and two Nb5+ atoms. In the fifth Se+1.92- site, Se+1.92- is bonded in a distorted single-bond geometry to four Ba2+ and one Nb5+ atom. In the sixth Se+1.92- site, Se+1.92- is bonded in a 2-coordinate geometry to four Ba2+ and two Nb5+ atoms.