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Updated: Oct 6, 2026

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
New efficient (aug-)pecS-n (n = 1, 2) basis sets for 19F NMR chemical shift quantum chemical calculations within the
Yuriy Yu Rusakov1, Irina L Rusakova1
1A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Favorsky St. 1, 664033 Irkutsk, Russia. i-rusakova@bk.ru.
Abstract:
New (aug-)pecS-n (n = 1, 2) basis sets for fluorine atoms, specifically optimized for the calculations of 19F NMR chemical shifts, are proposed. All parameters of these basis sets, including exponents and contraction coefficients, were optimized within the property-energy consistent (PEC) method. The (aug-)pecS-1 and (aug-)pecS-2 basis sets have the compositions [4s3p1d] ([5s4p2d]) and [5s4p2d1f] ([6s5p3d2f]), respectively. The performance of the developed fluorine basis sets was studied in the calculations of 19F NMR chemical shifts carried out within seven DFT models for a series of compounds containing fluorine atoms in versatile electronic environments. In all tests, new pecS-n (n = 1, 2) basis sets have demonstrated a superior accuracy over the commensurate basis sets that are most frequently used in such calculations. As a result, two computational DFT-based schemes are recommended for routine calculation of fluorine chemical shifts, the GIAO-DFT(B97-2)/aug-pecS-1(on F)//pecS-1(on the rest) and the GIAO-DFT(B97-2)/pecS-2, with the expected averaged absolute deviations of the theoretical values from the experiment being ca. 2.6 and 2.4 ppm, accordingly.
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