G factor for free electron

When interacting with such inclusions, water molecules are subjected to a shielding effect of ring currents in aromatic systems similar to the effect observed in EG. The value of g-factor that is close to g-factor for free electrons provides evidence for the validity of our argument. 

QED can be considered to be one of the most precisely tested theories in physics at present. It provides an extremely accurate description of systems such as hydrogen and helium atoms, as well as for bound-leptonic systems, for example, positronium and muonium. Remarkable agreement between theory and experiment has been achieved with respect to the determination of the hyperfine structure and the Lamb shift. The same holds true for the electronic and muonic g-factors. The free-electron g-factor is determined at present as... 

Hamiltonian matrix for the cubic ligand held, spin-orbit coupling and the electronic Zeeman interaction in the real cubic bases of a 2D term. The g-factor for the free electron has been set to two for clarity (Table A.l). 

The IS — 2S transition obeys the selection rule AF = 0, Am = 0 and is almost field-independent However, the g-factor for the bound electron is slightly less than for free space due to relativistic effects, and this gives the transition a small first-order field dependence. In the IS state the g-factor is g(lS) = g0 (1 - a2/3) [10]. The relativistic term is proportional to the binding energy so that g(2S) = ge (1 - a2/12). Thus, the field-dependence of the transition IS- 2S, (F=l,m=l AF=0,Am=0) leads to a frequency shift... 

The value of the g factor for the free electron is 2.002319. An experimentally determined value of the g factor different from this reflects the influence of the chemical environment. Particularly in transition metal ions and complexes, the value of the g factor is considerably affected by the influence of the chemical environment on the angular orbital momentum of the electron. 

The g-factor for a free electron is = 2.0023. The excitation frequencies in ESR spectra depend on the total magnetic moment. If we obtain a spectrum at known frequency and magnetic field, we can calculate the g-factor for our sample. The energy levels of a bound, unpaired electron differ... 

The ESR g-factor is also known as the Lande 7-factor or spectroscopic splitting factor and depends on the resonance condition for ESR (Eq. 3) and is independent of both applied field and frequency. The 7-factor of a free electron is 2.002322, while the 7-factors of organic free radicals, defect centers, transition metals, etc. depend on their electronic. structure. The 7-factors for free radicals are close to the free electron value but may vary from 0 to 9 for transition metal compounds. The most comprehensive compilations of 7-factors are those published in [75], [76]. The magnetic moments and hence 7-faclors of nuclei in crystalline and molecular environments are anisotropic, that is the 7-factor (and hyperfine interactions) depend on the orientation of the sample. In general, three principal 7-factors are encountered whose orientation dependence is given by ... 

The observed interval of the g-factor values at various a is characteristic of ARs. Therefore, in analyzing ESR spectra, the anisotropic magnetic parameters determined for low-molecular ARs were used [47]. It is commonly recognised for low-molecular ARs that the z axis is aligned with the 2p-orbital of the unpaired electron of the N atom, and that this direction determines the maximum value of the A -tensor and g-tensor value close to that for free electrons. The x axis is aligned with the N-O bond characterised by the maximum value of the g-tensor (2.0088-2.0104) and small (0.5-0.7 mT) A valne. The y axis determines a g-tensor value of 2.006-2.007, and the hyperfine coupling (HFC)-tensor value approximately corresponds to [55]. 

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