Materials Data on KHgI3 by Materials Project
KHgI3 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. K1+ is bonded to five I1- atoms to form distorted KI5 square pyramids that share corners with four equivalent HgI4 tetrahedra, edges with two equivalent KI5 square pyramids, and an edgeedge with one HgI4 tetrahedra. There are a spread of K–I bond distances ranging from 3.52–3.79 Å. Hg2+ is bonded to four I1- atoms to form HgI4 tetrahedra that share corners with four equivalent KI5 square pyramids, corners with two equivalent HgI4 tetrahedra, and an edgeedge with one KI5 square pyramid. There are a spread of Hg–I bond distances ranging from 2.79–2.96 Å. There are three inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to one K1+ and two equivalent Hg2+ atoms. In the second I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to two equivalent K1+ and one Hg2+ atom. In the third I1- site, I1- is bonded in a 3-coordinate geometry to two equivalent K1+ and one Hg2+ atom.