DOE OSTI2020
VN2H8O5F2NH4 is Iron carbide-derived structured and crystallizes in the orthorhombic P2_12_12_1 space group. The structure is zero-dimensional and consists of four ammonium molecules and four VN2H8O5F2 clusters. In each VN2H8O5F2 cluster, V5+ is bonded in a 7-coordinate geometry to five O2- and two F1- atoms. There are a spread of V–O bond distances ranging from 1.64–1.95 Å. There are one shorter (1.98 Å) and one longer (2.36 Å) V–F bond lengths. There are two inequivalent N+1.67- sites. In the first N+1.67- site, N+1.67- is bonded in a tetrahedral geometry to four H1+ atoms. There is one shorter (1.03 Å) and three longer (1.05 Å) N–H bond length. In the second N+1.67- site, N+1.67- is bonded in a tetrahedral geometry to four H1+ atoms. There is three shorter (1.04 Å) and one longer (1.05 Å) N–H bond length. There are eight inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N+1.67- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one N+1.67- and one O2- atom. The H–O bond length is 1.77 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N+1.67- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N+1.67- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one N+1.67- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one N+1.67- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one N+1.67- and one O2- atom. The H–O bond length is 1.77 Å. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one N+1.67- atom. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one V5+, one H1+, and one O2- atom. The O–O bond length is 1.47 Å. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one V5+ and one O2- atom. The O–O bond length is 1.46 Å. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one V5+ and one O2- atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one V5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one V5+, one H1+, and one O2- atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one V5+ atom. In the second F1- site, F1- is bonded in a 1-coordinate geometry to one V5+ atom.