Materials Data on KHg3 by Materials Project
KHg3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. K is bonded in a body-centered cubic geometry to fourteen Hg atoms. There are eight shorter (3.47 Å) and six longer (4.00 Å) K–Hg bond lengths. There are two inequivalent Hg sites. In the first Hg site, Hg is bonded to four equivalent K atoms to form HgK4 tetrahedra that share corners with twelve equivalent HgK6 octahedra, corners with sixteen equivalent HgK4 tetrahedra, edges with six equivalent HgK4 tetrahedra, and faces with four equivalent HgK6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the second Hg site, Hg is bonded to six equivalent K atoms to form distorted HgK6 octahedra that share corners with six equivalent HgK6 octahedra, corners with twenty-four equivalent HgK4 tetrahedra, edges with twelve equivalent HgK6 octahedra, and faces with eight equivalent HgK4 tetrahedra. The corner-sharing octahedral tilt angles are 0°.