Daniel Fredrickson, University of Wisconsin, Madison, USA, has developed a new theory that allows chemists to visualize the role of atomic size in shaping the crystal structures of inorganic compounds.

Atomic size has long been known to affect powerfully a crystal structure. However, at the electronic level of chemical bonds, the precise details of this relationship have remained unclear. Fredrickson’s density functional theory-chemical pressure (DFT-CP) analysis reveals how the effect of atomic size is most pronounced when the normal formation of bonds is impeded by steric repulsion at other contacts leading to non-ideal interatomic distances.

The research focused on intermetallic compounds to show how the concept of chemical pressure can be used to probe the effects of atomic size on bonding and crystal structure, but the approach could be applied to other structures entirely.

• DFT-Chemical Pressure Analysis: Visualizing the Role of Atomic Size in Shaping the Structures of Inorganic Materials,
  D. C. Fredrickson,
  J. Am. Chem. Soc. 2012.
  DOI: 10.1021/ja300685j