Calculations of influence of electric field on proton magnetic shielding in molecule,by means of Gell-Mann-Feynman theorem

A method is proposed for calculating the electric-field-linear contribution to the processional magnetic shielding of the nucleus, based on application on the Gell-Mann-Feyman theorem, using the Pade approximant. Calculational formulas have been derived for the first derivatives of the precessional magnetic shielding of the nucleus with respect to the electric field strength, these formulas containing either experimentally determinable characteristics of the molecules or characteristics obtained by interpolation of the observed properties of isoelectronic molecules. No calculations of wavefunctions are required. For hydrogen and hydrogen halide molecules, values have been calculated for the derivatives, with respect to electric field strength, of the precessional _H⁽¹⁾, prec and total _H⁽¹⁾proton magnetic shielding. The results are in good agreement with experimental data.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 21, No. 4, July–August, 1985.