Potential new high energy density materials: Cyclooctaoxygen O8, including comparisons with the well-known cyclo-S8 molecule

Abstract

The cyclic O8 molecule has been studied using ab initio quantum mechanical methods. Molecular structures were fully optimized at levels of theory up to and including second-order perturbation theory (MP2) using a double zeta plus polarization basis set. Parallel theoretical studies were carried out for the valance isoelectronic S8 molecule, for which much experimental data exists. With double zeta plus polarization (DZ+P) self-consistent-field (SCF) theory vibrational frequencies and infrared and Raman intensities have been predicted. Cyclo-O8 is considerably more stable than experimental O–O bond energies would suggest and is predicted to lie only 94 kcal/mol above four infinitely separated O2 molecules.