DOE OSTI2020
CsHgCl3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to twelve Cl1- atoms to form CsCl12 cuboctahedra that share corners with twelve CsCl12 cuboctahedra, faces with six CsCl12 cuboctahedra, and faces with eight HgCl6 octahedra. There are a spread of Cs–Cl bond distances ranging from 3.88–4.00 Å. In the second Cs1+ site, Cs1+ is bonded to twelve Cl1- atoms to form CsCl12 cuboctahedra that share corners with twelve CsCl12 cuboctahedra, faces with six CsCl12 cuboctahedra, and faces with eight HgCl6 octahedra. There are a spread of Cs–Cl bond distances ranging from 3.79–4.04 Å. In the third Cs1+ site, Cs1+ is bonded to twelve Cl1- atoms to form CsCl12 cuboctahedra that share corners with twelve CsCl12 cuboctahedra, faces with six CsCl12 cuboctahedra, and faces with eight HgCl6 octahedra. There are a spread of Cs–Cl bond distances ranging from 3.86–4.00 Å. There are three inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded to six Cl1- atoms to form HgCl6 octahedra that share corners with six HgCl6 octahedra and faces with eight CsCl12 cuboctahedra. The corner-sharing octahedra tilt angles range from 2–4°. There are a spread of Hg–Cl bond distances ranging from 2.47–3.10 Å. In the second Hg2+ site, Hg2+ is bonded to six Cl1- atoms to form HgCl6 octahedra that share corners with six HgCl6 octahedra and faces with eight CsCl12 cuboctahedra. The corner-sharing octahedra tilt angles range from 2–5°. There are a spread of Hg–Cl bond distances ranging from 2.38–3.04 Å. In the third Hg2+ site, Hg2+ is bonded to six Cl1- atoms to form HgCl6 octahedra that share corners with six HgCl6 octahedra and faces with eight CsCl12 cuboctahedra. The corner-sharing octahedra tilt angles range from 2–9°. There are a spread of Hg–Cl bond distances ranging from 2.55–3.19 Å. There are six inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 2-coordinate geometry to four Cs1+ and two Hg2+ atoms. In the second Cl1- site, Cl1- is bonded in a 2-coordinate geometry to four Cs1+ and two equivalent Hg2+ atoms. In the third Cl1- site, Cl1- is bonded in a 1-coordinate geometry to four Cs1+ and two Hg2+ atoms. In the fourth Cl1- site, Cl1- is bonded in a 1-coordinate geometry to four Cs1+ and two Hg2+ atoms. In the fifth Cl1- site, Cl1- is bonded in a 6-coordinate geometry to four Cs1+ and two Hg2+ atoms. In the sixth Cl1- site, Cl1- is bonded in a 6-coordinate geometry to four Cs1+ and two Hg2+ atoms.