Rb4Hg3Ge20 crystallizes in the cubic Pm-3n space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 12-coordinate geometry to four Hg(1,1,1) and eight Ge(2,2,2,2) atoms. In the second Rb site, Rb(1) is bonded in a 12-coordinate geometry to four equivalent Hg(1) and eight equivalent Ge(2) atoms. In the third Rb site, Rb(2) is bonded in a 20-coordinate geometry to eight Ge(1,1) and twelve Ge(2,2,2,2,2) atoms. There are three inequivalent Hg sites. In the first Hg site, Hg(1) is bonded to four Rb(1,1) and four Ge(2,2,2) atoms to form a mixture of distorted corner and edge-sharing HgRb4Ge4 tetrahedra. In the second Hg site, Hg(1) is bonded in a distorted body-centered cubic geometry to four equivalent Rb(1) and four equivalent Ge(2) atoms. In the third Hg site, Hg(1) is bonded to four equivalent Rb(1) and four equivalent Ge(2) atoms to form distorted corner-sharing HgRb4Ge4 tetrahedra. There are seven inequivalent Ge sites. In the first Ge site, Ge(2) is bonded in a 7-coordinate geometry to one Rb(2), two equivalent Rb(1), one Hg(1), one Ge(2), and two equivalent Ge(1) atoms. In the second Ge site, Ge(2) is bonded in a 7-coordinate geometry to one Rb(2), two equivalent Rb(1), one Hg(1), one Ge(2), and two equivalent Ge(1) atoms. In the third Ge site, Ge(2) is bonded in a 7-coordinate geometry to one Rb(2); two equivalent Rb(1); one Hg(1); one Ge(2); and two Ge(1,1) atoms. In the fourth Ge site, Ge(1) is bonded in a 5-coordinate geometry to one Rb(2); one Ge(1); and three Ge(2,2,2) atoms. In the fifth Ge site, Ge(1) is bonded in a 5-coordinate geometry to one Rb(2); one Ge(1); and three Ge(2,2,2) atoms. In the sixth Ge site, Ge(2) is bonded in a 7-coordinate geometry to one Rb(2), two equivalent Rb(1), one Hg(1), one Ge(2), and two equivalent Ge(1) atoms. In the seventh Ge site, Ge(2) is bonded in a 7-coordinate geometry to one Rb(2), two equivalent Rb(1), one Hg(1), one Ge(2), and two equivalent Ge(1) atoms.
Rb4Hg3Ge20 crystallizes in the cubic Pm-3n space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 12-coordinate geometry to four Hg(1,1,1) and eight Ge(2,2,2,2) atoms. All Rb(1)-Hg(1,1,1) bond lengths are 3.89 Å. All Rb(1)-Ge(2,2,2,2) bond lengths are 3.73 Å. In the second Rb site, Rb(1) is bonded in a 12-coordinate geometry to four equivalent Hg(1) and eight equivalent Ge(2) atoms. All Rb(1)-Hg(1) bond lengths are 3.89 Å. All Rb(1)-Ge(2) bond lengths are 3.73 Å. In the third Rb site, Rb(2) is bonded in a 20-coordinate geometry to eight Ge(1,1) and twelve Ge(2,2,2,2,2) atoms. All Rb(2)-Ge(1,1) bond lengths are 3.49 Å. All Rb(2)-Ge(2,2,2,2,2) bond lengths are 3.54 Å. There are three inequivalent Hg sites. In the first Hg site, Hg(1) is bonded to four Rb(1,1) and four Ge(2,2,2) atoms to form a mixture of distorted corner and edge-sharing HgRb4Ge4 tetrahedra. All Hg(1)-Ge(2,2,2) bond lengths are 2.65 Å. In the second Hg site, Hg(1) is bonded in a distorted body-centered cubic geometry to four equivalent Rb(1) and four equivalent Ge(2) atoms. All Hg(1)-Ge(2) bond lengths are 2.65 Å. In the third Hg site, Hg(1) is bonded to four equivalent Rb(1) and four equivalent Ge(2) atoms to form distorted corner-sharing HgRb4Ge4 tetrahedra. All Hg(1)-Ge(2) bond lengths are 2.65 Å. There are seven inequivalent Ge sites. In the first Ge site, Ge(2) is bonded in a 7-coordinate geometry to one Rb(2), two equivalent Rb(1), one Hg(1), one Ge(2), and two equivalent Ge(1) atoms. The Ge(2)-Ge(2) bond length is 2.50 Å. Both Ge(2)-Ge(1) bond lengths are 2.51 Å. In the second Ge site, Ge(2) is bonded in a 7-coordinate geometry to one Rb(2), two equivalent Rb(1), one Hg(1), one Ge(2), and two equivalent Ge(1) atoms. Both Ge(2)-Ge(1) bond lengths are 2.51 Å. In the third Ge site, Ge(2) is bonded in a 7-coordinate geometry to one Rb(2); two equivalent Rb(1); one Hg(1); one Ge(2); and two Ge(1,1) atoms. The Ge(2)-Ge(2) bond length is 2.50 Å. Both Ge(2)-Ge(1,1) bond lengths are 2.51 Å. In the fourth Ge site, Ge(1) is bonded in a 5-coordinate geometry to one Rb(2); one Ge(1); and three Ge(2,2,2) atoms. The Ge(1)-Ge(1) bond length is 2.54 Å. The Ge(1)-Ge(2) bond length is 2.51 Å. In the fifth Ge site, Ge(1) is bonded in a 5-coordinate geometry to one Rb(2); one Ge(1); and three Ge(2,2,2) atoms. The Ge(1)-Ge(1) bond length is 2.54 Å. The Ge(1)-Ge(2) bond length is 2.51 Å. In the sixth Ge site, Ge(2) is bonded in a 7-coordinate geometry to one Rb(2), two equivalent Rb(1), one Hg(1), one Ge(2), and two equivalent Ge(1) atoms. The Ge(2)-Ge(2) bond length is 2.50 Å. In the seventh Ge site, Ge(2) is bonded in a 7-coordinate geometry to one Rb(2), two equivalent Rb(1), one Hg(1), one Ge(2), and two equivalent Ge(1) atoms. The Ge(2)-Ge(2) bond length is 2.50 Å.