Line broadening mechanisms inhomogeneous

However, it should be emphasized that selective spectra of chromophores embedded in polymers or glasses have their own specific properties and they are the best tool to investigate chromophore-solvent interaction and the related motecular dynamics. Today there are many unanswered questions in this field. Some of these are is hole broadening in low-temperature domain due to the inhomogeneous sf ctral diffusion effect or the homogeneous line broadening mechanism manifests it f In what time scale does spectral diffusion exist Can the distribution over barriers and relaxation rates found for the extrinsic tunneling systons be extended for the intrinsic ones Certainly, this list questions is far from exhaustive. I hope the answers wfll be found in the not too distant future. 

An example is illustrated in Fig. 2. In case 1, there are two mechanisms operating one in the fast modulation limit, and one in the slow modulation limit. This is the classic case of combined homogeneous and inhomogeneous line broadening. In case 2, there is a single mechanism, but it is in the intermediate modulation region. The Raman hnewidths are identical... 

Q.y = y — g are the transition frequencies. F is a phemenological dephasing rate which accounts for both homogeneous (e.g., an interaction with bath) and inhomogeneous (e.g., static distribution of molecular transition frequencies) mechanisms of line broadening (for a review see ref 76). 

The third mechanism of inhomogeneous NMR line broadening in lanthanide ethylsul-fates is due to the presence of nuclear spins with different resonance frequencies. For instance, the H5B proton plays the role of an alien spin relative to the H5A proton in the same H2O molecule. The nuclear moments of lanthanide ions are also classified... 

Sharf, B. and Silbey, R. (1971) Near resonance interactions in the B-O scheme. The vibronic mechanism pertinent to radiationless transitions and inhomogeneous line broadening. Chem. Phys. Lett., 9, 125. 

Loring RA (1990) Statistical mechanical calculation of inhomogeneously broadened absorption line shapes in solution. J Phys Chem 94 513-515... 

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