Materials Data on CdHgAsBr by Materials Project
HgCdAsBr crystallizes in the orthorhombic Pmma space group. The structure is three-dimensional. there are two inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded in a rectangular see-saw-like geometry to two equivalent As3- and two equivalent Br1- atoms. Both Hg–As bond lengths are 2.55 Å. Both Hg–Br bond lengths are 3.62 Å. In the second Hg2+ site, Hg2+ is bonded in a linear geometry to two equivalent As3- atoms. Both Hg–As bond lengths are 2.56 Å. Cd2+ is bonded to two equivalent As3- and two Br1- atoms to form a mixture of edge and corner-sharing CdAs2Br2 trigonal pyramids. Both Cd–As bond lengths are 2.65 Å. There are one shorter (2.75 Å) and one longer (2.84 Å) Cd–Br bond lengths. As3- is bonded to two Hg2+ and two equivalent Cd2+ atoms to form corner-sharing AsCd2Hg2 trigonal pyramids. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a distorted L-shaped geometry to two equivalent Hg2+ and two equivalent Cd2+ atoms. In the second Br1- site, Br1- is bonded in an L-shaped geometry to two equivalent Cd2+ atoms.