Fe6BSi crystallizes in the orthorhombic Pmc2_1 space group. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 2-coordinate geometry to two equivalent B(1) atoms. In the second Fe site, Fe(2) is bonded in a 3-coordinate geometry to three equivalent Si(1) atoms. In the third Fe site, Fe(3) is bonded in a 2-coordinate geometry to two equivalent B(1) and one Si(1) atom. In the fourth Fe site, Fe(4) is bonded in a 3-coordinate geometry to one B(1) and two equivalent Si(1) atoms. B(1) is bonded in a 8-coordinate geometry to two equivalent Fe(1), two equivalent Fe(4), and four equivalent Fe(3) atoms. Si(1) is bonded in a 9-coordinate geometry to two equivalent Fe(3), three equivalent Fe(2), and four equivalent Fe(4) atoms.
Fe6BSi crystallizes in the orthorhombic Pmc2_1 space group. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 2-coordinate geometry to two equivalent B(1) atoms. There is one shorter (2.19 Å) and one longer (2.20 Å) Fe(1)-B(1) bond length. In the second Fe site, Fe(2) is bonded in a 3-coordinate geometry to three equivalent Si(1) atoms. There are two shorter (2.29 Å) and one longer (2.45 Å) Fe(2)-Si(1) bond length. In the third Fe site, Fe(3) is bonded in a 2-coordinate geometry to two equivalent B(1) and one Si(1) atom. There is one shorter (2.08 Å) and one longer (2.12 Å) Fe(3)-B(1) bond length. The Fe(3)-Si(1) bond length is 2.46 Å. In the fourth Fe site, Fe(4) is bonded in a 3-coordinate geometry to one B(1) and two equivalent Si(1) atoms. The Fe(4)-B(1) bond length is 2.19 Å. There is one shorter (2.26 Å) and one longer (2.29 Å) Fe(4)-Si(1) bond length. B(1) is bonded in a 8-coordinate geometry to two equivalent Fe(1), two equivalent Fe(4), and four equivalent Fe(3) atoms. Si(1) is bonded in a 9-coordinate geometry to two equivalent Fe(3), three equivalent Fe(2), and four equivalent Fe(4) atoms.