K5Sb4 crystallizes in the monoclinic Cm space group. There are five inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to two equivalent Sb(1), two equivalent Sb(4), and three equivalent Sb(3) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to two equivalent Sb(2), two equivalent Sb(3), and three equivalent Sb(4) atoms. In the third K site, K(3) is bonded in a 6-coordinate geometry to one Sb(2), two equivalent Sb(3), and three equivalent Sb(1) atoms. In the fourth K site, K(4) is bonded in a 6-coordinate geometry to one Sb(1), two equivalent Sb(4), and three equivalent Sb(2) atoms. In the fifth K site, K(5) is bonded in a distorted square co-planar geometry to two equivalent Sb(1) and two equivalent Sb(2) atoms. There are four inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 9-coordinate geometry to one K(4), two equivalent K(1), two equivalent K(5), three equivalent K(3), and one Sb(3) atom. In the second Sb site, Sb(2) is bonded in a 9-coordinate geometry to one K(3), two equivalent K(2), two equivalent K(5), three equivalent K(4), and one Sb(4) atom. In the third Sb site, Sb(3) is bonded in a 9-coordinate geometry to two equivalent K(2), two equivalent K(3), three equivalent K(1), one Sb(1), and one Sb(4) atom. In the fourth Sb site, Sb(4) is bonded in a 9-coordinate geometry to two equivalent K(1), two equivalent K(4), three equivalent K(2), one Sb(2), and one Sb(3) atom.
K5Sb4 crystallizes in the monoclinic Cm space group. There are five inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to two equivalent Sb(1), two equivalent Sb(4), and three equivalent Sb(3) atoms. Both K(1)-Sb(1) bond lengths are 3.69 Å. Both K(1)-Sb(4) bond lengths are 3.70 Å. There is one shorter (3.69 Å) and two longer (3.78 Å) K(1)-Sb(3) bond lengths. In the second K site, K(2) is bonded in a 7-coordinate geometry to two equivalent Sb(2), two equivalent Sb(3), and three equivalent Sb(4) atoms. Both K(2)-Sb(2) bond lengths are 3.71 Å. Both K(2)-Sb(3) bond lengths are 3.69 Å. There is one shorter (3.70 Å) and two longer (3.78 Å) K(2)-Sb(4) bond lengths. In the third K site, K(3) is bonded in a 6-coordinate geometry to one Sb(2), two equivalent Sb(3), and three equivalent Sb(1) atoms. The K(3)-Sb(2) bond length is 3.79 Å. Both K(3)-Sb(3) bond lengths are 3.75 Å. All K(3)-Sb(1) bond lengths are 3.75 Å. In the fourth K site, K(4) is bonded in a 6-coordinate geometry to one Sb(1), two equivalent Sb(4), and three equivalent Sb(2) atoms. The K(4)-Sb(1) bond length is 3.84 Å. Both K(4)-Sb(4) bond lengths are 3.73 Å. There are two shorter (3.69 Å) and one longer (3.83 Å) K(4)-Sb(2) bond length. In the fifth K site, K(5) is bonded in a distorted square co-planar geometry to two equivalent Sb(1) and two equivalent Sb(2) atoms. Both K(5)-Sb(1) bond lengths are 3.58 Å. Both K(5)-Sb(2) bond lengths are 3.59 Å. There are four inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 9-coordinate geometry to one K(4), two equivalent K(1), two equivalent K(5), three equivalent K(3), and one Sb(3) atom. The Sb(1)-Sb(3) bond length is 2.83 Å. In the second Sb site, Sb(2) is bonded in a 9-coordinate geometry to one K(3), two equivalent K(2), two equivalent K(5), three equivalent K(4), and one Sb(4) atom. The Sb(2)-Sb(4) bond length is 2.83 Å. In the third Sb site, Sb(3) is bonded in a 9-coordinate geometry to two equivalent K(2), two equivalent K(3), three equivalent K(1), one Sb(1), and one Sb(4) atom. The Sb(3)-Sb(4) bond length is 2.87 Å. In the fourth Sb site, Sb(4) is bonded in a 9-coordinate geometry to two equivalent K(1), two equivalent K(4), three equivalent K(2), one Sb(2), and one Sb(3) atom.