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Inclusion of hydrogen p orbitals in the semiempirical calculation of NMR parameters. I. Influence on the FPT INDO spin–spin coupling constants

✍ Scribed by J. C. Facell; R. H. Contreras

Publisher
John Wiley and Sons
Year
1980
Tongue
English
Weight
494 KB
Volume
18
Category
Article
ISSN
0020-7608

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✦ Synopsis

Abstract

Hydrogen 2__p__ orbitals have been introduced into the basis set to calculate the Fermi contact term of spin–spin coupling constants using the FPT INDO method. Different coupling constants show different sensitivity to these hydrogen polarization functions. Some improvements are found for molecules containing N or F. Calculations of proton‐proton geminal coupling constants give more negative results than those of FPT INDO, yielding a better agreement with experimental values. The π‐transmission mechanism is notably exaggerated.

📜 SIMILAR VOLUMES

Inclusion of hydrogen p orbitals in the
Inclusion of hydrogen p orbitals in the semiempirical calculation of NMR parameters. III: INDO CHF calculations of orbital and dipolar contributions to spin–spin coupling constants involving protons
✍ J. C. Facelli; R. H. Contreras 📂 Article 📅 1981 🏛 John Wiley and Sons 🌐 English ⚖ 497 KB

## Abstract The self‐consistent perturbation theory is used to calculate noncontract contributions to spin–spin coupling constants involving protons. Molecular wave functions were obtained with a modified version of the INDO method which includes hydrogen 2__p__ orbitals in its basis set. It is fou

Influence of the INDO parameterization o
Influence of the INDO parameterization on the indirect spin–spin coupling constants as calculated by the FPT INDO method
✍ R. H. Contreras; A. R. Engelmann; G. E. Scuseria; J. C. Facelli 📂 Article 📅 1980 🏛 John Wiley and Sons 🌐 English ⚖ 542 KB

## Abstract Alterations have been introduced in the semi‐empirical INDO parameters in order to study their influence on the Fermi contact term of the indirect spin–spin coupling constants as calculated by the finite perturbation theory (FPT). For this purpose a set of molecules containing hydrogen,