| Autor: |
Colombo Jofré MT; Instituto de Modelado e Innovación Tecnológica (UNNE-CONICET), Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Avda. Libertad, 5460 Corrientes, Argentina., Kozioł K; Narodowe Centrum Badań Jądrowych (NCBJ), Andrzeja Sołtana 7, 05-400 Otwock-Świerk, Poland., Aucar IA; Instituto de Modelado e Innovación Tecnológica (UNNE-CONICET), Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Avda. Libertad, 5460 Corrientes, Argentina., Gaul K; Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany., Berger R; Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany., Aucar GA; Instituto de Modelado e Innovación Tecnológica (UNNE-CONICET), Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Avda. Libertad, 5460 Corrientes, Argentina. |
| Abstrakt: |
The indirect spin-spin coupling tensor, J, between mercury nuclei in systems containing this element can be of the order of a few kHz and one of the largest measured. We analyzed the physics behind the electronic mechanisms that contribute to the one- and two-bond couplings n J Hg-Hg (n = 1, 2). For doing so, we performed calculations for J-couplings in the ionized X 2 2+ and X 3 2+ linear molecules (X = Zn, Cd, Hg) within polarization propagator theory using the random phase approximation and the pure zeroth-order approximation with Dirac-Hartree-Fock and Dirac-Kohn-Sham orbitals, both at four-component and zeroth-order regular approximation levels. We show that the "paramagnetic-like" mechanism contributes more than 99.98% to the total isotropic value of the coupling tensor. By analyzing the molecular and atomic orbitals involved in the total value of the response function, we find that the s-type valence atomic orbitals have a predominant role in the description of the coupling. This fact allows us to develop an effective model from which quantum electrodynamics (QED) effects on J-couplings in the aforementioned ions can be estimated. Those effects were found to be within the interval (0.7; 1.7)% of the total relativistic effect on isotropic one-bond 1 J coupling, though ranging those corrections between the interval (-0.4; -0.2)% in Zn-containing ions, to (-1.2; -0.8)% in Hg-containing ions, of the total isotropic coupling constant in the studied systems. The estimated QED corrections show a visible dependence on the nuclear charge Z of each atom X in the form of a power-law proportional to Z X 5 . |
