Materials Data on NbSeF9 by Materials Project
NbSeF9 is alpha Po structured and crystallizes in the trigonal R3 space group. The structure is zero-dimensional and consists of three NbSeF9 clusters. there are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six F1- atoms to form NbF6 octahedra that share corners with three SeF6 octahedra. The corner-sharing octahedra tilt angles range from 2–3°. There is three shorter (1.89 Å) and three longer (2.00 Å) Nb–F bond length. In the second Nb5+ site, Nb5+ is bonded to six F1- atoms to form NbF6 octahedra that share corners with three equivalent SeF6 octahedra. The corner-sharing octahedral tilt angles are 1°. There is three shorter (1.89 Å) and three longer (2.00 Å) Nb–F bond length. There are two inequivalent Se4+ sites. In the first Se4+ site, Se4+ is bonded to six F1- atoms to form distorted SeF6 octahedra that share corners with three NbF6 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. There are a spread of Se–F bond distances ranging from 1.73–2.37 Å. In the second Se4+ site, Se4+ is bonded to six F1- atoms to form distorted SeF6 octahedra that share corners with three equivalent NbF6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are three shorter (1.74 Å) and three longer (2.36 Å) Se–F bond lengths. There are twelve inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Nb5+ atom. In the second F1- site, F1- is bonded in a distorted linear geometry to one Nb5+ and one Se4+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Nb5+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one Nb5+ atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one Se4+ atom. In the sixth F1- site, F1- is bonded in a single-bond geometry to one Se4+ atom. In the seventh F1- site, F1- is bonded in a single-bond geometry to one Nb5+ atom. In the eighth F1- site, F1- is bonded in a distorted linear geometry to one Nb5+ and one Se4+ atom. In the ninth F1- site, F1- is bonded in a single-bond geometry to one Se4+ atom. In the tenth F1- site, F1- is bonded in a single-bond geometry to one Se4+ atom. In the eleventh F1- site, F1- is bonded in a distorted linear geometry to one Nb5+ and one Se4+ atom. In the twelfth F1- site, F1- is bonded in a distorted linear geometry to one Nb5+ and one Se4+ atom.