Fe2Si crystallizes in the trigonal P-3m1 space group. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted body-centered cubic geometry to three equivalent Fe(2) and five equivalent Si(1) atoms. In the second Fe site, Fe(2) is bonded in a 14-coordinate geometry to two equivalent Fe(3), six equivalent Fe(1), and six equivalent Si(1) atoms. In the third Fe site, Fe(3) is bonded in a distorted body-centered cubic geometry to two equivalent Fe(2) and six equivalent Si(1) atoms. Si(1) is bonded in a distorted body-centered cubic geometry to three equivalent Fe(2), three equivalent Fe(3), and five equivalent Fe(1) atoms.
Fe2Si crystallizes in the trigonal P-3m1 space group. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted body-centered cubic geometry to three equivalent Fe(2) and five equivalent Si(1) atoms. All Fe(1)-Fe(2) bond lengths are 2.41 Å. There are a spread of Fe(1)-Si(1) bond distances ranging from 2.35-2.42 Å. In the second Fe site, Fe(2) is bonded in a 14-coordinate geometry to two equivalent Fe(3), six equivalent Fe(1), and six equivalent Si(1) atoms. Both Fe(2)-Fe(3) bond lengths are 2.41 Å. All Fe(2)-Si(1) bond lengths are 2.73 Å. In the third Fe site, Fe(3) is bonded in a distorted body-centered cubic geometry to two equivalent Fe(2) and six equivalent Si(1) atoms. All Fe(3)-Si(1) bond lengths are 2.41 Å. Si(1) is bonded in a distorted body-centered cubic geometry to three equivalent Fe(2), three equivalent Fe(3), and five equivalent Fe(1) atoms.