Two-step photodissociation of O2 with a total excitation energy of 7.7 eV yields O(1D) atoms with their angular momenta aligned perpendicular to the fragment recoil axis. Correlation rules linking the bound molecule with the separated atoms predict such strong alignment only for an adiabatic process.

J. Chem. Phys.

Eppink, A. T. J. B., Parker, D. H., Janssen, M. H. M., Buijsse, B., & van der Zande, W. J. (1998). Production of maximally aligned O(1D) atoms from two-step photodissociation of molecular oxygen. J. Chem. Phys., 108, 1305–1308.