Fig. 2.

Atomic volumes in the bcc (Gray Squares) and sc (Black Circles) phases, relative to those in the fcc structure. In the horizontal axis the elements are arranged by the metallic radius in the fcc phase. All results are based on present GGA calculations. Whereas bcc phases have similar densities to fcc (and for most elements are even slightly denser), hypothetical sc phases are usually less dense, except C, Li and Ba. It is clear that predictions of the hard-sphere model are inconsistent with ab initio calculations.