K4Si23 crystallizes in the cubic Pm-3n space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 20-coordinate geometry to eight Si(2,2,2,2) and twelve Si(3,3,3,3) atoms. In the second K site, K(2) is bonded in a 12-coordinate geometry to four Si(1,1) and eight Si(3,3,3,3) atoms. There are ten inequivalent Si sites. In the first Si site, Si(3) is bonded in a 7-coordinate geometry to one K(1); two equivalent K(2); one Si(1); one Si(3); and two Si(2,2) atoms. In the second Si site, Si(3) is bonded in a 7-coordinate geometry to one K(1); two equivalent K(2); one Si(1); one Si(3); and two Si(2,2) atoms. In the third Si site, Si(1) is bonded to four equivalent K(2) and four Si(3,3) atoms to form distorted corner-sharing SiK4Si4 tetrahedra. In the fourth Si site, Si(1) is bonded in a distorted body-centered cubic geometry to four equivalent K(2) and four Si(3,3) atoms. In the fifth Si site, Si(2) is bonded in a 5-coordinate geometry to one K(1), one Si(2), and three equivalent Si(3) atoms. In the sixth Si site, Si(2) is bonded in a 5-coordinate geometry to one K(1); one Si(2); and three Si(3,3,3) atoms. In the seventh Si site, Si(2) is bonded in a 5-coordinate geometry to one K(1), one Si(2), and three equivalent Si(3) atoms. In the eighth Si site, Si(2) is bonded in a 5-coordinate geometry to one K(1); one Si(2); and three Si(3,3,3) atoms. In the ninth Si site, Si(3) is bonded in a 7-coordinate geometry to one K(1); two equivalent K(2); one Si(1); one Si(3); and two Si(2,2) atoms. In the tenth Si site, Si(3) is bonded in a 7-coordinate geometry to one K(1); two equivalent K(2); one Si(1); one Si(3); and two Si(2,2) atoms.
K4Si23 crystallizes in the cubic Pm-3n space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 20-coordinate geometry to eight Si(2,2,2,2) and twelve Si(3,3,3,3) atoms. All K(1)-Si(2,2,2,2) bond lengths are 3.30 Å. All K(1)-Si(3,3,3,3) bond lengths are 3.38 Å. In the second K site, K(2) is bonded in a 12-coordinate geometry to four Si(1,1) and eight Si(3,3,3,3) atoms. All K(2)-Si(1,1) bond lengths are 3.64 Å. All K(2)-Si(3,3,3,3) bond lengths are 3.47 Å. There are ten inequivalent Si sites. In the first Si site, Si(3) is bonded in a 7-coordinate geometry to one K(1); two equivalent K(2); one Si(1); one Si(3); and two Si(2,2) atoms. The Si(3)-Si(1) bond length is 2.41 Å. The Si(3)-Si(3) bond length is 2.44 Å. Both Si(3)-Si(2,2) bond lengths are 2.38 Å. In the second Si site, Si(3) is bonded in a 7-coordinate geometry to one K(1); two equivalent K(2); one Si(1); one Si(3); and two Si(2,2) atoms. The Si(3)-Si(1) bond length is 2.41 Å. The Si(3)-Si(3) bond length is 2.44 Å. Both Si(3)-Si(2,2) bond lengths are 2.38 Å. In the third Si site, Si(1) is bonded to four equivalent K(2) and four Si(3,3) atoms to form distorted corner-sharing SiK4Si4 tetrahedra. All Si(1)-Si(3,3) bond lengths are 2.41 Å. In the fourth Si site, Si(1) is bonded in a distorted body-centered cubic geometry to four equivalent K(2) and four Si(3,3) atoms. In the fifth Si site, Si(2) is bonded in a 5-coordinate geometry to one K(1), one Si(2), and three equivalent Si(3) atoms. The Si(2)-Si(2) bond length is 2.32 Å. All Si(2)-Si(3) bond lengths are 2.38 Å. In the sixth Si site, Si(2) is bonded in a 5-coordinate geometry to one K(1); one Si(2); and three Si(3,3,3) atoms. The Si(2)-Si(2) bond length is 2.32 Å. The Si(2)-Si(3) bond length is 2.38 Å. In the seventh Si site, Si(2) is bonded in a 5-coordinate geometry to one K(1), one Si(2), and three equivalent Si(3) atoms. The Si(2)-Si(2) bond length is 2.32 Å. In the eighth Si site, Si(2) is bonded in a 5-coordinate geometry to one K(1); one Si(2); and three Si(3,3,3) atoms. The Si(2)-Si(2) bond length is 2.32 Å. Both Si(2)-Si(3,3) bond lengths are 2.38 Å. In the ninth Si site, Si(3) is bonded in a 7-coordinate geometry to one K(1); two equivalent K(2); one Si(1); one Si(3); and two Si(2,2) atoms. In the tenth Si site, Si(3) is bonded in a 7-coordinate geometry to one K(1); two equivalent K(2); one Si(1); one Si(3); and two Si(2,2) atoms.