Basis set convergence study of the atomization energy, geometry, and anharmonic force field of SO2: The importance of inner polarization functions
- 15 February 1998
- journal article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 108 (7), 2791-2800
- https://doi.org/10.1063/1.475670
Abstract
The total atomization energies, geometries, and anharmonic force fields of the SO and SO2 molecules have been studied at the augmented coupled cluster [CCSD(T)] level near the one-particle basis set limit. The effect of core correlation has been accounted for. The addition of high-exponent d and f “inner polarization functions” to the sulfur basis set was found to be essential for obtaining reliable molecular geometries. The differential effect of core correlation on computed properties is in fact much less important. The CCSD(T) one-particle basis set limit for the symmetric stretching frequencies appears to be higher than the exact value, while the antisymmetric stretching frequency benefits from an error cancellation. The basis set extension effects of diffuse functions and inner polarization functions appear to be nearly perfectly additive. Our best computed atomization energies and geometries agree to within 0.1 kcal/mol, 0.0004 Å, and 0.03 degrees with experiment: The errors in the fundamentals of SO2 are +3.9, −0.4, and +0.4 cm−1. The best computed quartic force field for SO2 should provide a good starting point for a new experimental refinement.Keywords
This publication has 57 references indexed in Scilit:
- The rotational levels of the ground vibrational state of formaldehydeMolecular Physics, 1997
- An accurate quartic force field for formaldehydeThe Journal of Chemical Physics, 1996
- Investigating optimal coordinates for describing vibrational motionTheoretical Chemistry Accounts, 1995
- Electron affinities of the first-row atoms revisited. Systematic basis sets and wave functionsThe Journal of Chemical Physics, 1992
- A comparison of the efficiency and accuracy of the quadratic configuration interaction (QCISD), coupled cluster (CCSD), and Brueckner coupled cluster (BCCD) methodsChemical Physics Letters, 1992
- Comparison of coupled-cluster methods which include the effects of connected triple excitationsThe Journal of Chemical Physics, 1990
- An efficient procedure for the calculation of the vibrational energy levels of any triatomic moleculeMolecular Physics, 1986
- Analytical potentials for triatomic moleculesMolecular Physics, 1982
- A full coupled-cluster singles and doubles model: The inclusion of disconnected triplesThe Journal of Chemical Physics, 1982
- The Infrared Spectrum and Molecular Constants of Sulfur DioxideThe Journal of Chemical Physics, 1953