K5Se3 crystallizes in the triclinic P1 space group. There are ten inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one Se(2), one Se(4), one Se(5), one Se(6), and two equivalent Se(1) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to one Se(3), one Se(4), one Se(5), one Se(6), and two equivalent Se(1) atoms. In the third K site, K(3) is bonded in a 6-coordinate geometry to one Se(1), one Se(2), one Se(5), one Se(6), and two equivalent Se(3) atoms. In the fourth K site, K(4) is bonded in a 6-coordinate geometry to one Se(1), one Se(3), one Se(5), one Se(6), and two equivalent Se(2) atoms. In the fifth K site, K(5) is bonded in a 4-coordinate geometry to one Se(1), one Se(2), one Se(3), and one Se(4) atom. In the sixth K site, K(6) is bonded in a 4-coordinate geometry to one Se(1), one Se(2), one Se(3), and one Se(4) atom. In the seventh K site, K(7) is bonded in a 6-coordinate geometry to one Se(2), one Se(4), one Se(5), one Se(6), and two equivalent Se(3) atoms. In the eighth K site, K(8) is bonded in a 6-coordinate geometry to one Se(3), one Se(4), one Se(5), one Se(6), and two equivalent Se(2) atoms. In the ninth K site, K(9) is bonded in a 6-coordinate geometry to one Se(1), one Se(2), one Se(5), one Se(6), and two equivalent Se(4) atoms. In the tenth K site, K(10) is bonded in a 6-coordinate geometry to one Se(1), one Se(3), one Se(5), one Se(6), and two equivalent Se(4) atoms. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded in a 10-coordinate geometry to one K(10), one K(3), one K(4), one K(5), one K(6), one K(9), two equivalent K(1), and two equivalent K(2) atoms. In the second Se site, Se(2) is bonded in a 10-coordinate geometry to one K(1), one K(3), one K(5), one K(6), one K(7), one K(9), two equivalent K(4), and two equivalent K(8) atoms. In the third Se site, Se(3) is bonded in a 10-coordinate geometry to one K(10), one K(2), one K(4), one K(5), one K(6), one K(8), two equivalent K(3), and two equivalent K(7) atoms. In the fourth Se site, Se(4) is bonded in a 10-coordinate geometry to one K(1), one K(2), one K(5), one K(6), one K(7), one K(8), two equivalent K(10), and two equivalent K(9) atoms. In the fifth Se site, Se(5) is bonded in a 9-coordinate geometry to one K(1), one K(10), one K(2), one K(3), one K(4), one K(7), one K(8), one K(9), and one Se(6) atom. In the sixth Se site, Se(6) is bonded in a 9-coordinate geometry to one K(1), one K(10), one K(2), one K(3), one K(4), one K(7), one K(8), one K(9), and one Se(5) atom.
K5Se3 crystallizes in the triclinic P1 space group. There are ten inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one Se(2), one Se(4), one Se(5), one Se(6), and two equivalent Se(1) atoms. The K(1)-Se(2) bond length is 3.55 Å. The K(1)-Se(4) bond length is 3.38 Å. The K(1)-Se(5) bond length is 3.51 Å. The K(1)-Se(6) bond length is 3.53 Å. There is one shorter (3.55 Å) and one longer (3.61 Å) K(1)-Se(1) bond length. In the second K site, K(2) is bonded in a 6-coordinate geometry to one Se(3), one Se(4), one Se(5), one Se(6), and two equivalent Se(1) atoms. The K(2)-Se(3) bond length is 3.56 Å. The K(2)-Se(4) bond length is 3.40 Å. The K(2)-Se(5) bond length is 3.36 Å. The K(2)-Se(6) bond length is 3.36 Å. There is one shorter (3.48 Å) and one longer (3.50 Å) K(2)-Se(1) bond length. In the third K site, K(3) is bonded in a 6-coordinate geometry to one Se(1), one Se(2), one Se(5), one Se(6), and two equivalent Se(3) atoms. The K(3)-Se(1) bond length is 3.53 Å. The K(3)-Se(2) bond length is 3.38 Å. The K(3)-Se(5) bond length is 3.53 Å. The K(3)-Se(6) bond length is 3.53 Å. There is one shorter (3.57 Å) and one longer (3.58 Å) K(3)-Se(3) bond length. In the fourth K site, K(4) is bonded in a 6-coordinate geometry to one Se(1), one Se(3), one Se(5), one Se(6), and two equivalent Se(2) atoms. The K(4)-Se(1) bond length is 3.59 Å. The K(4)-Se(3) bond length is 3.39 Å. The K(4)-Se(5) bond length is 3.35 Å. The K(4)-Se(6) bond length is 3.35 Å. Both K(4)-Se(2) bond lengths are 3.50 Å. In the fifth K site, K(5) is bonded in a 4-coordinate geometry to one Se(1), one Se(2), one Se(3), and one Se(4) atom. The K(5)-Se(1) bond length is 3.21 Å. The K(5)-Se(2) bond length is 3.21 Å. The K(5)-Se(3) bond length is 3.20 Å. The K(5)-Se(4) bond length is 3.21 Å. In the sixth K site, K(6) is bonded in a 4-coordinate geometry to one Se(1), one Se(2), one Se(3), and one Se(4) atom. The K(6)-Se(1) bond length is 3.21 Å. The K(6)-Se(2) bond length is 3.21 Å. The K(6)-Se(3) bond length is 3.22 Å. The K(6)-Se(4) bond length is 3.21 Å. In the seventh K site, K(7) is bonded in a 6-coordinate geometry to one Se(2), one Se(4), one Se(5), one Se(6), and two equivalent Se(3) atoms. The K(7)-Se(2) bond length is 3.40 Å. The K(7)-Se(4) bond length is 3.55 Å. The K(7)-Se(5) bond length is 3.37 Å. The K(7)-Se(6) bond length is 3.35 Å. There is one shorter (3.49 Å) and one longer (3.51 Å) K(7)-Se(3) bond length. In the eighth K site, K(8) is bonded in a 6-coordinate geometry to one Se(3), one Se(4), one Se(5), one Se(6), and two equivalent Se(2) atoms. The K(8)-Se(3) bond length is 3.38 Å. The K(8)-Se(4) bond length is 3.55 Å. The K(8)-Se(5) bond length is 3.53 Å. The K(8)-Se(6) bond length is 3.52 Å. There is one shorter (3.57 Å) and one longer (3.58 Å) K(8)-Se(2) bond length. In the ninth K site, K(9) is bonded in a 6-coordinate geometry to one Se(1), one Se(2), one Se(5), one Se(6), and two equivalent Se(4) atoms. The K(9)-Se(1) bond length is 3.40 Å. The K(9)-Se(2) bond length is 3.57 Å. The K(9)-Se(5) bond length is 3.36 Å. The K(9)-Se(6) bond length is 3.36 Å. There is one shorter (3.48 Å) and one longer (3.51 Å) K(9)-Se(4) bond length. In the tenth K site, K(10) is bonded in a 6-coordinate geometry to one Se(1), one Se(3), one Se(5), one Se(6), and two equivalent Se(4) atoms. The K(10)-Se(1) bond length is 3.38 Å. The K(10)-Se(3) bond length is 3.54 Å. The K(10)-Se(5) bond length is 3.52 Å. The K(10)-Se(6) bond length is 3.52 Å. There is one shorter (3.58 Å) and one longer (3.59 Å) K(10)-Se(4) bond length. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded in a 10-coordinate geometry to one K(10), one K(3), one K(4), one K(5), one K(6), one K(9), two equivalent K(1), and two equivalent K(2) atoms. In the second Se site, Se(2) is bonded in a 10-coordinate geometry to one K(1), one K(3), one K(5), one K(6), one K(7), one K(9), two equivalent K(4), and two equivalent K(8) atoms. In the third Se site, Se(3) is bonded in a 10-coordinate geometry to one K(10), one K(2), one K(4), one K(5), one K(6), one K(8), two equivalent K(3), and two equivalent K(7) atoms. In the fourth Se site, Se(4) is bonded in a 10-coordinate geometry to one K(1), one K(2), one K(5), one K(6), one K(7), one K(8), two equivalent K(10), and two equivalent K(9) atoms. In the fifth Se site, Se(5) is bonded in a 9-coordinate geometry to one K(1), one K(10), one K(2), one K(3), one K(4), one K(7), one K(8), one K(9), and one Se(6) atom. The Se(5)-Se(6) bond length is 2.42 Å. In the sixth Se site, Se(6) is bonded in a 9-coordinate geometry to one K(1), one K(10), one K(2), one K(3), one K(4), one K(7), one K(8), one K(9), and one Se(5) atom.