Open AccessAssessment of CCSD(T)-F12 Approximations and Basis Sets for Harmonic Vibrational Frequencies
Author(s) -
Jan M. L. Martin,
Manoj K. Kesharwani
Publication year - 2014
Publication title -
journal of chemical theory and computation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.001
H-Index - 185
eISSN - 1549-9626
pISSN - 1549-9618
DOI - 10.1021/ct500174q
Subject(s) - basis set , valence (chemistry) , limit (mathematics) , basis (linear algebra) , physics , mathematics , computational chemistry , quantum mechanics , chemistry , mathematical analysis , molecule , geometry
We consider basis set convergence and the effect of various approximations to CCSD(T)-F12 for a representative sample of harmonic frequencies (the HFREQ2014 set). CCSD(T*)(F12*)/cc-pVDZ-F12 offers a particularly favorable compromise between accuracy and computational cost: its RMSD <3 cm(-1) from the valence CCSD(T) limit is actually less than the remaining discrepancy with the experimental value at the valence CCSD(T) limit (about 5 cm(-1) RMSD). CCSD(T)-F12a and CCSD(T)-F12b appear to benefit from error compensation between CCSD and (T).