7-radiation hyperfine structure parameters

The beta decay of in an iodine compound often leads to a xenon compound with the same ligands. The Mossbauer spectrum of the gamma radiation emitted from the Xe nuclei so formed shows hyperfine structure. This is due to the nuclear electric quadrupole moment eQ of the excited Xe nucleus, which results in a doublet absorption spectrum if the electric field gradient eq —d VIdz ) does not vanish. The observed quadrupole splitting equals e qQ 2 if the asymmetry parameter of the electric field gradient is negligible. (See Chapter 2.)... 

ESR spectra can provide not only an unambiguous assignment of radicals, but also experimental information about their geometrical and electronic structures and reactions. CW-ESR spectroscopy combined with matrix isolation methods and ionizing radiation (y-ray, X-ray, etc.) is applied to the studies on reactive intermediate radicals including anionic and cationic species trapped in low temperature solid matrices. ESR parameters, especially hyperfine (hf) couplings, are predicted with considerable precision by recent advances in computational methods such as density functional theory (DFT), which affords a valuable bridge between experiment and theory at a most fundamental level. 

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