On the accuracy factors and computational cost of the GIAO-DFT calculation of 15 N NMR chemical shifts of amides
Copyright © 2017 John Wiley & Sons, Ltd.
| Veröffentlicht in: | Magnetic resonance in chemistry : MRC. - 1985. - 55(2017), 11 vom: 10. Nov., Seite 1015-1021 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2017
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| Zugriff auf das übergeordnete Werk: | Magnetic resonance in chemistry : MRC |
| Schlagworte: | Journal Article 15N NMR GIAO-DFT amides chemical shift locally dense basis set magnetic shielding constant |
| Zusammenfassung: | Copyright © 2017 John Wiley & Sons, Ltd. The main factors affecting the accuracy and computational cost of Gauge-independent Atomic Orbital-density functional theory (GIAO-DFT) calculation of 15 N NMR chemical shifts in the benchmark series of 16 amides are considered. Among those are the choice of the DFT functional and basis set, solvent effects, internal reference conversion factor and applicability of the locally dense basis set (LDBS) scheme. Solvent effects are treated within the polarizable continuum model (PCM) scheme as well as at supermolecular level with solvent molecules considered in explicit way. The best result is found for Keal and Tozer's KT3 functional used in combination with Jensen's pcS-3 basis set with taking into account solvent effects within the polarizable continuum model. The proposed LDBS scheme implies pcS-3 on nitrogen and pc-2 elsewhere in the molecule. The resulting mean average error for the calculated 15 N NMR chemical shifts is about 6 ppm. The application of the LDBS approach tested in a series of 16 amides results in a dramatic decrease in computational cost (more than an order of magnitude in time scale) with insignificant loss of accuracy |
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| Beschreibung: | Date Completed 05.03.2018 Date Revised 05.03.2018 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1097-458X |
| DOI: | 10.1002/mrc.4625 |