Calcul des déplacements chimiques par la méthode des perturbations finies au niveau INDO avec GIAO et approximation de London. I. ¹³C et ¹H

Abstract

A formalism for the calculation of σ in the finite perturbation method is developed by keeping hermitian the first order perturbed matrix in B. The σ formalism is separated into mono, di, and triatomic terms, and the importance of the electron densities of neighboring and remote bonds is shown. 13 C chemical shifts depend only slightly on the remote bonds in contrast to those for 1 H. A calculation of the screening constant for a series of 16 sp and sp 2 carbons gives an average precision of 5 ppm for the 13 C nuclei. [Journal Translation]