Materials Data on Ga2Hg5Se8 by Materials Project
Hg5Ga2Se8 crystallizes in the tetragonal I-4m2 space group. The structure is three-dimensional. there are two inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded to four equivalent Se2- atoms to form HgSe4 tetrahedra that share corners with four equivalent GaSe4 tetrahedra and corners with eight equivalent HgSe4 tetrahedra. All Hg–Se bond lengths are 2.71 Å. In the second Hg2+ site, Hg2+ is bonded to four Se2- atoms to form HgSe4 tetrahedra that share corners with four equivalent GaSe4 tetrahedra and corners with six HgSe4 tetrahedra. There are two shorter (2.67 Å) and two longer (2.77 Å) Hg–Se bond lengths. Ga3+ is bonded to four Se2- atoms to form GaSe4 tetrahedra that share corners with ten HgSe4 tetrahedra. There are two shorter (2.44 Å) and two longer (2.51 Å) Ga–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Hg2+ and one Ga3+ atom. In the second Se2- site, Se2- is bonded to three Hg2+ and one Ga3+ atom to form corner-sharing SeGaHg3 tetrahedra.