Spin-orbit effect, paramagnetic

All molecules will show an MCD spectrum. The spectrum of many types of molecule can now be simulated, often through more than one theoretical approach. Several areas need further study however. It would be useful if all types of MCD spectrum could be calculated at a range of levels of theory so that a scientist interested in predicting a spectrum would be able to choose an approach that suitably fits their needs. More benchmark calculations are needed to improve our understanding of the limitations of the present methods. These calculations would be aided by the availability of more high-quality spectra of small molecules that would be suitable test cases. While the MCD spectra of many molecules can now be calculated, one area that probably still cannot be studied with confidence is paramagnetic molecules that include very heavy elements. In this case spin-orbit effects will be very large and perturbational treatments like those applied thus far are unlikely to provide accurate results. 

Ag is the variation of the g-tensor components from 2.0023. This interaction arises from the coupling of the paramagnetic moment to the lattice through spin-orbit coupling as was derived by Moriya by extending Anderson s superexchange model " to include the spin-orbit effect. 

NMR Hamiltonian (p. 768) non-homogeneous electric field (p. 729) nonlinear response (p. 733) nuclear magneton (p. 757) oscillating electric field (p. 752) paramagnetic effect (p. 780) paramagnetic spin-orbit (p. 782)... 

Zeeman operator and the spin-orbit coupling (also called paramagnetic spin-orbit term). A ° and A/ are generally small and of opposite sign, so that their effects tend to cancel one another. For transition metal ions, the g-anisotropy and the deviation from the free electron value mainly come from the third contribution, which is usually the most difficult to calculate. Thus, a proper treatment of the spin-orbit coupling (SOC) is crucial for the g-tensor calculation. 

Ramsey theory (p. 666) diamagnetic effect (p. 668) paramagnetic effect (p. 668) coupling constant (p. 668) direct spin-spin interaction (p. 669) diamagnetic spin-orbit contribution (p. 669) paramagnetic spin-orbit (p. 670) spin-dipole contribution (p. 670)... 

EOM-CC), to projected coupled cluster theory with all single and double excitations (CCSD) ° As an additional requirements there are (e) the use of enough large basis sets with augmented basis functions to obtain reliable evalution of paramagnetic spin-orbit (PSO) and spin-dipole (SD) terms (f) the inclusion of vibrational corrections for the SSCC, and (g) the consideration of solvent effects on SSCCs. " The latter two requirements concern the comparison of calculated and measured SSCCs. 

Consideration of the spin-orbit interaction and the effect of an external magnetic field on the electronic ground state of an ion in a CF allows evaluation of the various terms in the spin-Hamiltonian of Equation (31). In addition, the interaction of the nucleus of the paramagnetic ion and ligand nuclei with the d-electron cloud must be considered. In this way the experimentally determined terms of the spin-Hamiltonian may be related to such parameters as the energy differences between levels of the ion in the CF and amount of charge transfer between d-electrons and ligands. 

The broadly successful application of these formulas to the paramagnetism of lanthanide complexes was due to the wide multiplet widths in the/block metals (large spin—orbit coupling coefficients X) and to the small effect of the ligand field on the deep-lying / orbitals. No comparably useful formula for the magnetic moments of d block complexes exists, except perhaps for the spin-only formula ... 

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