K6Na14HgTl18 crystallizes in the cubic Pm-3 space group. K(1) is bonded in a 15-coordinate geometry to one K(1), four equivalent Na(1), four equivalent Na(2), and six equivalent Tl(1) atoms. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to three equivalent K(1), three equivalent Tl(1), and three equivalent Tl(2) atoms. In the second Na site, Na(2) is bonded to four equivalent K(1), two equivalent Tl(1), and two equivalent Tl(2) atoms to form distorted NaK4Tl4 tetrahedra that share corners with two equivalent Hg(1)Tl12 cuboctahedra, corners with eight equivalent Na(2)K4Tl4 tetrahedra,  an edgeedge with one Na(2)K4Tl4 tetrahedra, and  a faceface with one Na(2)K4Tl4 tetrahedra. Hg(1) is bonded to twelve equivalent Tl(1) atoms to form HgTl12 cuboctahedra that share corners with twelve equivalent Na(2)K4Tl4 tetrahedra. There are two inequivalent Tl sites. In the first Tl site, Tl(2) is bonded in a 6-coordinate geometry to two equivalent Na(2) and four equivalent Na(1) atoms. In the second Tl site, Tl(1) is bonded in a 12-coordinate geometry to three equivalent K(1), one Na(2), two equivalent Na(1), one Hg(1), and five equivalent Tl(1) atoms.
K6Na14HgTl18 crystallizes in the cubic Pm-3 space group. K(1) is bonded in a 15-coordinate geometry to one K(1), four equivalent Na(1), four equivalent Na(2), and six equivalent Tl(1) atoms. The K(1)-K(1) bond length is 4.08 Å. All K(1)-Na(1) bond lengths are 4.01 Å. There are two shorter (3.87 Å) and two longer (4.13 Å) K(1)-Na(2) bond lengths. There are four shorter (3.76 Å) and two longer (3.82 Å) K(1)-Tl(1) bond lengths. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to three equivalent K(1), three equivalent Tl(1), and three equivalent Tl(2) atoms. All Na(1)-Tl(1) bond lengths are 3.36 Å. All Na(1)-Tl(2) bond lengths are 3.37 Å. In the second Na site, Na(2) is bonded to four equivalent K(1), two equivalent Tl(1), and two equivalent Tl(2) atoms to form distorted NaK4Tl4 tetrahedra that share corners with two equivalent Hg(1)Tl12 cuboctahedra, corners with eight equivalent Na(2)K4Tl4 tetrahedra,  an edgeedge with one Na(2)K4Tl4 tetrahedra, and  a faceface with one Na(2)K4Tl4 tetrahedra. Both Na(2)-Tl(1) bond lengths are 3.28 Å. Both Na(2)-Tl(2) bond lengths are 3.56 Å. Hg(1) is bonded to twelve equivalent Tl(1) atoms to form HgTl12 cuboctahedra that share corners with twelve equivalent Na(2)K4Tl4 tetrahedra. All Hg(1)-Tl(1) bond lengths are 3.24 Å. There are two inequivalent Tl sites. In the first Tl site, Tl(2) is bonded in a 6-coordinate geometry to two equivalent Na(2) and four equivalent Na(1) atoms. In the second Tl site, Tl(1) is bonded in a 12-coordinate geometry to three equivalent K(1), one Na(2), two equivalent Na(1), one Hg(1), and five equivalent Tl(1) atoms. There is one shorter (3.38 Å) and four longer (3.42 Å) Tl(1)-Tl(1) bond lengths.