Materials Data on BAsH4NO4F by Materials Project

Abstract

NH4BAsO4F crystallizes in the monoclinic Cc space group. The structure is two-dimensional and consists of four ammonium molecules and two BAsO4F sheets oriented in the (0, 0, 1) direction. In each BAsO4F sheet, B3+ is bonded to three O2- and one F1- atom to form BO3F tetrahedra that share corners with three equivalent AsO4 tetrahedra. All B–O bond lengths are 1.48 Å. The B–F bond length is 1.42 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with three equivalent BO3F tetrahedra. There is one shorter (1.68 Å) and three longer (1.74 Å) As–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one B3+ and one As5+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one As5+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one B3+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one B3+ and one As5+ atom. F1- is bonded in a single-bond geometry to one B3+ atom.