Landd factor

The iodine molecule has been very thoroughly studied with electric and magnetic level-crossing spectroscopy. The hyperfine structure of the rotational levels affects the profile of the level-crossing curves [849]. A computer fit to the non-Lorentzian superposition of all Hanle curves from the different hfs levels allows simultaneous determination of the Landd factor g and the lifetime t [850]. Because of different predissociation rates the effective lifetimes of different hfs levels differ considerably. 

In larger molecules the phase-coherence time of excited levels may be shorter than the population lifetime because of perturbations between closely spaced levels of different electronic states, which cause a dephasing of the excited-level wave functions. One example is the NO2 molecule, where the width of the Hanle signal turns out to be more than one order of magnitude larger than expected from independent measurements of population lifetime and Landd factors [851, 852]. This discrepancy is explained by a short intramolecular decay time (dephasing time), but a much larger radiative lifetime [853]. 

Then, once the nuclear spin is known, the electronic Landd factor, gj, can be determined to high precision. In the early atomic beam experiments there was, however, little... 

It was noted in Chapter 4 that the Madelung constant of a structure may be expressed in various ways. The way that is conceptually simplest in terms of the Bom-Landd equation is the simple geometric factor. A, such that when combined with the true ionic charges, Z and Z. the correct electrostatic enetgy is formulated. It was noted that some workers have favored using another constant. A, combined with the highest common factor of Z and Z, Z. ... 

A characteristic feature of lanthanide (III) compounds is that only the term distances dependent on phenomenological parameters of interelectronic repulsion are significantly diminished by the nephelauxetic effect, whereas the spin-orbit Landd parameter 4f hardly changes at all. In a delocalized L.C.A.O. description where the electronic density of the partly filled shell on the central atom is depleted by being multiplied by the factor (1 - a ), is expected to be multiplied by the same factor, whereas the nephelauxetic ratio /3 should be... 

By substituting tlie values gj=gg/2 = l into equation (3.84), an approximate expression for the Landd g-factor is obtained... 

---