Ab initio study of C4O4 in Td symmetry

An ab initio study on the hypothetical molecule C4O4 in Td symmetry is presented. Calculations have been performed at the SCF and MP2 levels using different basis sets, 3s2p, 3s2p1d and, only for SCF, 4s3p2d. The structure is found to have a minimum and the geometry is nearly cubic. At the highest possible level of accuracy, SCF with 4s3p2d, and MP2 with 3s2p1d basis sets, the second derivatives of the energy were found to be positive, implying a stable structure. The energy release of the dissociation reaction is high, approximately 350 kcal/mol, although somewhat lower than the one computed for cubic N8. Based on this estimate, we conclude that C4D4 is a good candidate for a high energy-density material.