Fe11Si5 is Tungsten-derived structured and crystallizes in the cubic Pm-3m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted body-centered cubic geometry to three equivalent Fe(2), one Si(1), one Si(3), and three equivalent Si(2) atoms. In the second Fe site, Fe(2) is bonded in a 14-coordinate geometry to eight equivalent Fe(1), two equivalent Si(3), and four equivalent Si(2) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a body-centered cubic geometry to eight equivalent Fe(1) atoms. In the second Si site, Si(2) is bonded in a distorted body-centered cubic geometry to four equivalent Fe(2) and eight equivalent Fe(1) atoms. In the third Si site, Si(3) is bonded in a distorted body-centered cubic geometry to six equivalent Fe(2) and eight equivalent Fe(1) atoms.
Fe11Si5 is Tungsten-derived structured and crystallizes in the cubic Pm-3m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted body-centered cubic geometry to three equivalent Fe(2), one Si(1), one Si(3), and three equivalent Si(2) atoms. All Fe(1)-Fe(2) bond lengths are 2.40 Å. The Fe(1)-Si(1) bond length is 2.37 Å. The Fe(1)-Si(3) bond length is 2.42 Å. All Fe(1)-Si(2) bond lengths are 2.39 Å. In the second Fe site, Fe(2) is bonded in a 14-coordinate geometry to eight equivalent Fe(1), two equivalent Si(3), and four equivalent Si(2) atoms. Both Fe(2)-Si(3) bond lengths are 2.77 Å. All Fe(2)-Si(2) bond lengths are 2.77 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a body-centered cubic geometry to eight equivalent Fe(1) atoms. In the second Si site, Si(2) is bonded in a distorted body-centered cubic geometry to four equivalent Fe(2) and eight equivalent Fe(1) atoms. In the third Si site, Si(3) is bonded in a distorted body-centered cubic geometry to six equivalent Fe(2) and eight equivalent Fe(1) atoms.