Intermolecular Bonding in Solid Oxygen

Inelastic x-ray scattering of dense solid oxygen: Evidence for intermolecular bonding in solid oxygen
Meng, Y., P.J. Eng, J.S. Tse, D.M. Shaw, M.Y. Hu, J. Shu, S.A. Gramsch, C. Kao, R.J. Hemley,
and H.-K. Mao. PNAS, 105, 11640, (2008)

The e–phase of oxygen, which consists of (O2)4 clusters, displays the bonding characteristics of a closed-shell system. Increasing interactions between (O2)4 clusters develop upon compression of the e-phase, and provide a potential mechanism for intercluster bonding in still higher-pressure phases.

Variation in the s* and p* transition energies of oxygen with pressure. The correlation between s* transition energy and volume is shown in the Inset.