Ab initio study of the intermolecular potential energy surface for the ground electronic state of the O-2-CO system and prediction of second virial coefficients

作者：Tashakor Saeedeh; Noorbala Mohammad R^*; Namazian Mansoor

来源：Theoretical Chemistry Accounts, 2017, 136(10): 118.

DOI：10.1007/s00214-017-2158-z

• Intermolecular potential energy surface
• O-2-CO system
• Complete basis set limit
• Second virial coefficient
• Beattie-Bridgeman equation of state

The intermolecular potential energy surface of complex pairing the ground electronic state of oxygen molecule (X-3 Sigma(-)(g)) with carbon monoxide is calculated using the CCSD(T) method. The interaction energies obtained using the aug-cc-pVDZ and aug-cc-pVTZ basis sets are extrapolated to the complete basis set limit using the latest extrapolated scheme. The interaction energies were calculated by the supermolecular approach with the full counterpoise correction for the basis set superposition error. The effects of the orientation angle and dihedral angle on the stability of the system were studied by considering 1260 energy points of the O-2-CO system. The results show that the interaction energy strongly depends on the orientation of two molecules. The second virial coefficients calculated using the potential energy surface are in good agreement with those obtained by the parameters of the Beattie-Bridgeman equation that regards the states of pure oxygen and carbon monoxide fluids.

• 出版日期2017-10-10