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Assessing spin-component-scaled second-order Møller-plesset theory using anharmonic frequencies

Domin, Dominik; Benoit, David M.


Dominik Domin

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Dr David Benoit
Senior Lecturer in Molecular Physics and Astrochemistry


Four common parametrisations of spin-component-scaled second-order Møller–Plesset (MP2) theory are benchmarked by calculating the anharmonic vibrational frequencies of a test suite consisting of eighteen diatomic and five small molecules. Of the four methods, the scaled opposite-spin MP2 (SOS-MP2), the variable-scaling opposite-spin MP2 (VOS-MP2) and the spin-component-scaled MP2 (SCS-MP2) methods perform statistically better than standard MP2 theory, while the spin-com- ponent scaled for nucleic bases MP2 (SCSN-MP2) performs worse. Vibrations of closed-shell diatomic molecules are slightly more accurately described by the SOS-MP2 method of Head-Gordon (εMAD = 51 cm-1) than the SCS-MP2 method of Grimme (εMAD = 61 cm-1) or the size-consistent parametrisation of VOS-MP2 (εMAD = 54 cm-1). For open-shell diatomic molecules, the SOS-MP2 (εMAD = 83 cm-1) and SCS-MP2 (εMAD = 81 cm-1) methods are of similar accuracy, while VOS-MP2 is slightly better (εMAD = 77 cm-1). Since the VOS-MP2 and SOS- MP2 methods tend to have smaller deviations from experi- ment, and they can be made computationally more economical than the SCS-MP2 or MP2 methods, we suggest that they should be the preferred ab initio method for computing vibrational frequencies in large molecules.


Domin, D., & Benoit, D. M. (2011). Assessing spin-component-scaled second-order Møller-plesset theory using anharmonic frequencies. Chemphyschem, 12(17), 3383-3391.

Journal Article Type Article
Online Publication Date Nov 8, 2011
Publication Date Dec 9, 2011
Print ISSN 1439-7641
Electronic ISSN 1439-7641
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 12
Issue 17
Pages 3383-3391
Keywords Ab initio calculations; Computational chemistry; Electronic structure; Moller-Plesset theory; Vibrational spectroscopy
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