Materials Data on Hg2Pb(SI)2 by Materials Project
Hg2Pb(SI)2 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Hg2+ is bonded to two equivalent S2- and four I1- atoms to form a mixture of distorted corner, edge, and face-sharing HgS2I4 octahedra. The corner-sharing octahedra tilt angles range from 0–63°. There are one shorter (2.43 Å) and one longer (2.44 Å) Hg–S bond lengths. There are two shorter (3.38 Å) and two longer (3.51 Å) Hg–I bond lengths. Pb2+ is bonded in a 7-coordinate geometry to four equivalent S2- and three I1- atoms. All Pb–S bond lengths are 3.05 Å. There are one shorter (3.30 Å) and two longer (3.56 Å) Pb–I bond lengths. S2- is bonded in a 2-coordinate geometry to two equivalent Hg2+ and two equivalent Pb2+ atoms. There are three inequivalent I1- sites. In the first I1- site, I1- is bonded to four equivalent Hg2+ and one Pb2+ atom to form edge-sharing IHg4Pb square pyramids. In the second I1- site, I1- is bonded in a 4-coordinate geometry to four equivalent Pb2+ atoms. In the third I1- site, I1- is bonded in a body-centered cubic geometry to eight equivalent Hg2+ atoms.