Bestimmung der Abschirmung der magnetischen Kernresonanz und der magnetischen Suszeptibilität durch Berechnung der Stromdichte diamagnetischer Moleküle mit der Methode der finiten Elemente

Determination of the NMR-Shielding and of Magnetic Susceptibility by Calculation of the Current Density of Diamagnetic Molecules by the Finite Element Method In paper [20] the finite element method was initiated for calculations of diamagnetic properties of molecules on the basis of a semiclassical approach [18, 19]. In the present work this method is used in the frame of the uncoupled Hartree-Fock-perturbation theory. It is shown that the proposed approach is applicable to localized orbitals, the susceptibility and the shielding being divided into incrementary contributions. Furthermore the relationship to the semiclassical approach and to the approach of Rebane [7] is shown. The H₂-molecule, the threedimensional anisotropic harmonic oscillator and the CH₄-molecule serve as examples to present the possibilities of this method.