Fe3Si crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 8-coordinate geometry to four equivalent Fe(2) and four equivalent Si(1) atoms. In the second Fe site, Fe(2) is bonded in a 14-coordinate geometry to four equivalent Fe(2), eight equivalent Fe(1), and two equivalent Si(1) atoms. Si(1) is bonded in a distorted body-centered cubic geometry to two equivalent Fe(2) and eight equivalent Fe(1) atoms.
Fe3Si crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 8-coordinate geometry to four equivalent Fe(2) and four equivalent Si(1) atoms. All Fe(1)-Fe(2) bond lengths are 2.46 Å. All Fe(1)-Si(1) bond lengths are 2.41 Å. In the second Fe site, Fe(2) is bonded in a 14-coordinate geometry to four equivalent Fe(2), eight equivalent Fe(1), and two equivalent Si(1) atoms. All Fe(2)-Fe(2) bond lengths are 2.84 Å. Both Fe(2)-Si(1) bond lengths are 2.75 Å. Si(1) is bonded in a distorted body-centered cubic geometry to two equivalent Fe(2) and eight equivalent Fe(1) atoms.