Materials Data on SrNb5Se8 by Materials Project
SrNb5Se8 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Sr2+ is bonded in a distorted q6 geometry to ten Se2- atoms. There are a spread of Sr–Se bond distances ranging from 3.22–3.48 Å. There are three inequivalent Nb+2.80+ sites. In the first Nb+2.80+ site, Nb+2.80+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing NbSe6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are four shorter (2.65 Å) and two longer (2.68 Å) Nb–Se bond lengths. In the second Nb+2.80+ site, Nb+2.80+ is bonded to six Se2- atoms to form a mixture of distorted edge, corner, and face-sharing NbSe6 octahedra. The corner-sharing octahedra tilt angles range from 50–53°. There are a spread of Nb–Se bond distances ranging from 2.53–2.87 Å. In the third Nb+2.80+ site, Nb+2.80+ is bonded to six Se2- atoms to form a mixture of distorted edge, corner, and face-sharing NbSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–53°. There are a spread of Nb–Se bond distances ranging from 2.58–2.84 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to one Sr2+ and four Nb+2.80+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three Nb+2.80+ atoms. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to two equivalent Sr2+ and three equivalent Nb+2.80+ atoms. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to five Nb+2.80+ atoms.