Materials Data on K6Na14MgTl18 by Materials Project

Abstract

K6Na14MgTl18 crystallizes in the cubic Pm-3 space group. The structure is three-dimensional. K is bonded in a 6-coordinate geometry to one K, eight Na, and six equivalent Tl atoms. The K–K bond length is 4.06 Å. There are a spread of K–Na bond distances ranging from 3.85–4.11 Å. There are four shorter (3.75 Å) and two longer (3.81 Å) K–Tl bond lengths. There are two inequivalent Na sites. In the first Na site, Na is bonded in a 6-coordinate geometry to three equivalent K and six Tl atoms. All Na–Tl bond lengths are 3.35 Å. In the second Na site, Na is bonded to four equivalent K and four Tl atoms to form distorted NaK4Tl4 tetrahedra that share corners with two equivalent MgTl12 cuboctahedra, corners with eight equivalent NaK4Tl4 tetrahedra, an edgeedge with one NaK4Tl4 tetrahedra, and a faceface with one NaK4Tl4 tetrahedra. There are two shorter (3.27 Å) and two longer (3.54 Å) Na–Tl bond lengths. Mg is bonded to twelve equivalent Tl atoms to form MgTl12 cuboctahedra that share corners with twelve equivalent NaK4Tl4 tetrahedra. All Mg–Tl bond lengths are 3.21 Å. There are two inequivalent Tl sites. In the first Tl site, Tl is bonded in a 6-coordinate geometry to six Na atoms. In the second Tl site, Tl is bonded in a 12-coordinate geometry to three equivalent K, three Na, one Mg, and five equivalent Tl atoms. There are one shorter (3.34 Å) and four longer (3.39 Å) Tl–Tl bond lengths.