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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.

Journal Article Type Article
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
APA6 Citation Domin, D., & Benoit, D. M. (2011). Assessing spin-component-scaled second-order Møller-plesset theory using anharmonic frequencies. Chemphyschem, 12(17), 3383-3391.
Keywords Ab initio calculations; Computational chemistry; Electronic structure; Moller-Plesset theory; Vibrational spectroscopy