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Surprising Performance for Vibrational Frequencies of the Distinguishable Clusters with Singles and Doubles (DCSD) and MP2.5 Approximations
- Source :
- AIP Conference Proceedings 1906, 030005 (2017)
- Publication Year :
- 2017
-
Abstract
- We show that the DCSD (distinguishable clusters with all singles and doubles) correlation method permits the calculation of vibrational spectra at near-CCSD(T) quality but at no more than CCSD cost, and with comparatively inexpensive analytical gradients. For systems dominated by a single reference configuration, even MP2.5 is a viable alternative, at MP3 cost. MP2.5 performance for vibrational frequencies is comparable to double hybrids such as DSD-PBEP86-D3BJ, but without resorting to empirical parameters. DCSD is also quite suitable for computing zero-point vibrational energies in computational thermochemistry.<br />Comment: AIP Conference Proceedings, in press (ICCMSE-2017 proceedings), 4 pages
- Subjects :
- Physics - Chemical Physics
Subjects
Details
- Database :
- arXiv
- Journal :
- AIP Conference Proceedings 1906, 030005 (2017)
- Publication Type :
- Report
- Accession number :
- edsarx.1705.01889
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1063/1.5012284