DOE OSTI2020
Hg3(OI)2BF4 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four BF4 clusters and two Hg3(OI)2 sheets oriented in the (0, 1, 0) direction. In each BF4 cluster, B is bonded in a tetrahedral geometry to four F atoms. There are a spread of B–F bond distances ranging from 1.38–1.46 Å. There are four inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one B atom. In the second F site, F is bonded in a single-bond geometry to one B atom. In the third F site, F is bonded in a single-bond geometry to one B atom. In the fourth F site, F is bonded in a single-bond geometry to one B atom. In each Hg3(OI)2 sheet, there are three inequivalent Hg sites. In the first Hg site, Hg is bonded in a linear geometry to two O atoms. There are one shorter (2.03 Å) and one longer (2.06 Å) Hg–O bond lengths. In the second Hg site, Hg is bonded in a 4-coordinate geometry to two O and two I atoms. There are one shorter (2.15 Å) and one longer (2.30 Å) Hg–O bond lengths. There are one shorter (2.67 Å) and one longer (3.17 Å) Hg–I bond lengths. In the third Hg site, Hg is bonded in a 3-coordinate geometry to two O and one I atom. There are one shorter (2.18 Å) and one longer (2.37 Å) Hg–O bond lengths. The Hg–I bond length is 2.66 Å. There are two inequivalent O sites. In the first O site, O is bonded in a trigonal planar geometry to three Hg atoms. In the second O site, O is bonded in a distorted trigonal non-coplanar geometry to three Hg atoms. There are two inequivalent I sites. In the first I site, I is bonded in a single-bond geometry to one Hg atom. In the second I site, I is bonded in a distorted L-shaped geometry to two Hg atoms.