Highly correlated systems: Structure, binding energy and harmonic vibrational frequencies of ozone

✍ Scribed by Krishnan Raghavachari; Gary W. Trucks; John A. Pople; Eric Replogle

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 514 KB
• Volume: 158
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(89)87322-1

✦ Synopsis

The structure, binding energy and harmonic vibrational frequencies of 0, are calculated using the quadratic configuration interaction (QCI) method with a variety ofbasis sets. This method reproduces the geometry and vibrational frequencies ofozone fairly accurateiy using both restricted (RHF) and unrestricted Hartree-Fock (UHF) starting points. The asymmetric stretching frequency of ozone, which is extremely scnsitivc to the level of electron correlation, is calculated with a deviation of about 10% from expcnment. The symmetric frequencies are calculated with errors of l-596. The vibrational frequencies do not depend greatly on the level of correlation if a UHF starting point is used. The atomization energy is also accurately calculated, using a composite method where the effects of larger basis sets are evaluated using fourth-order perturbation theory.