Materials Data on CdHg4(AsI2)2 by Materials Project
(Hg2As)2(CdI4) crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are four inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded to two As3- and three I1- atoms to form HgAs2I3 trigonal bipyramids that share corners with three equivalent CdI4 tetrahedra, corners with two equivalent HgAs2I3 trigonal bipyramids, and an edgeedge with one HgAs2I3 trigonal bipyramid. Both Hg–As bond lengths are 2.57 Å. There are a spread of Hg–I bond distances ranging from 3.48–3.54 Å. In the second Hg2+ site, Hg2+ is bonded in a distorted rectangular see-saw-like geometry to two As3- and two I1- atoms. There are one shorter (2.57 Å) and one longer (2.58 Å) Hg–As bond lengths. There are one shorter (3.39 Å) and one longer (3.63 Å) Hg–I bond lengths. In the third Hg2+ site, Hg2+ is bonded in a 6-coordinate geometry to two As3- and four I1- atoms. There are one shorter (2.57 Å) and one longer (2.58 Å) Hg–As bond lengths. There are a spread of Hg–I bond distances ranging from 3.58–3.86 Å. In the fourth Hg2+ site, Hg2+ is bonded to two As3- and three I1- atoms to form distorted HgAs2I3 trigonal bipyramids that share corners with three equivalent CdI4 tetrahedra, corners with two equivalent HgAs2I3 trigonal bipyramids, and an edgeedge with one HgAs2I3 trigonal bipyramid. Both Hg–As bond lengths are 2.57 Å. There are a spread of Hg–I bond distances ranging from 3.44–3.87 Å. Cd2+ is bonded to four I1- atoms to form CdI4 tetrahedra that share corners with six HgAs2I3 trigonal bipyramids. There are a spread of Cd–I bond distances ranging from 2.81–2.87 Å. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded to four Hg2+ atoms to form corner-sharing AsHg4 tetrahedra. In the second As3- site, As3- is bonded to four Hg2+ atoms to form corner-sharing AsHg4 tetrahedra. There are four inequivalent I1- sites. In the first I1- site, I1- is bonded in a 1-coordinate geometry to three Hg2+ and one Cd2+ atom. In the second I1- site, I1- is bonded in a 1-coordinate geometry to three Hg2+ and one Cd2+ atom. In the third I1- site, I1- is bonded in a 1-coordinate geometry to three Hg2+ and one Cd2+ atom. In the fourth I1- site, I1- is bonded in a 1-coordinate geometry to three Hg2+ and one Cd2+ atom.