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

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 2p orbitals in its basis set. It is found that in many cases the orbital and dipolar terms are by no means negligible, being particularly important in geminal HH couplings. Results reported in this paper for this type of coupling, reproduce experimental trends in the series CH4, NH3, and OH2. In general, noncontact terms are found to decrease as the number of bonds separating the interacting nuclei increases. Copyright © 1981 John Wiley & Sons, Inc.

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Author Julio Cesar Facelli Biostatistics & Bioinformatics, Division of Translational Bi ...