Materials Data on H5S2NO7 by Materials Project
NH4HS2O7 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four ammonium molecules and two HS2O7 clusters. In each HS2O7 cluster, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.53 Å) H–O bond length. There are two inequivalent S2+ sites. In the first S2+ site, S2+ is bonded to four O2- atoms to form corner-sharing SO4 tetrahedra. There are a spread of S–O bond distances ranging from 1.43–1.61 Å. In the second S2+ site, S2+ is bonded to four O2- atoms to form corner-sharing SO4 tetrahedra. There are a spread of S–O bond distances ranging from 1.45–1.74 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one S2+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one S2+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one H1+ and one S2+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one S2+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one S2+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one H1+ and one S2+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two S2+ atoms.