title: Vibrational frequency scaling factors for correlation consistent basis sets and the methods CC2 and MP2 and their spin-scaled SCS and SOS variants.
abstract: We present scaling factors for vibrational frequencies calculated within the harmonic approximation and the correlated wave-function methods coupled cluster singles and doubles model (CC2) and Møller-Plesset perturbation theory (MP2) with and without a spin-component scaling (SCS or spin-opposite scaling (SOS)). Frequency scaling factors and the remaining deviations from the reference data are evaluated for several non-augmented basis sets of the cc-pVXZ family of generally contracted correlation-consistent basis sets as well as for the segmented contracted TZVPP basis. We find that the SCS and SOS variants of CC2 and MP2 lead to a slightly better accuracy for the scaled vibrational frequencies. The determined frequency scaling factors can also be used for vibrational frequencies calculated for excited states through response theory with CC2 and the algebraic diagrammatic construction through second order and their spin-component scaled variants.
authors.affiliation: Centre for Theoretical and Computational Chemistry CTCC, Department of Chemistry, University of Tromsø, N-9037 Tromsø, Norway.
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Friese
authors.affiliation: Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, D-44801 Bochum, Germany.
authors.forename: Lisa
authors.initials: L
authors.lastname: Törk
authors.affiliation: Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, D-44801 Bochum, Germany.
authors.forename: Christof
authors.initials: C
authors.lastname: Hättig