354. BRILL, R. [X-Ray Investigation of the Iron Carbonyl, Fe2(CO)9.] Ztschr. Krist., vol. 65, 1927, pp. 85-93; Chem. Abs., vol. 21, 1927, p. 3775.

354. BRILL, R. [X-Ray Investigation of the Iron Carbonyl, Fe₂(CO)₉.] Ztschr. Krist., vol. 65, 1927, pp. 85-93; Chem. Abs., vol. 21, 1927, p. 3775.

Fe2(CO)9 is hexagonal with a unit cell of the dimensions a=6.45 and c=15.8 Å. U., which contains 4 mol. The space group may be C⁶₆, C⁴_r6, C²_h6, D⁶₆, or D⁴_h6. The 9 CO groups are at the corners of 2 octahedrons with a common face. The Fe atoms are on the trigonal axis perpendicular to this common face.