Absorption band shapes

Champion P M and Albrecht A C 1981 On the modeling of absorption band shapes and resonance Raman excitation profiles Chem. Phys. Lett. 82 410-13... 

The absorption band shape is necessarily dictated by those same intramolecular trapping and solvent vibrations which determine the rate of thermal electron transfer since the change in electronic distribution is the same for the two processes. The band shape depends on the product of two terms. The first is the transition moment M = the square of which determines the... 

FIGURE 1.2 (a) The interaction of electromagnetic radiation with a metal center promotes an electron from the ground state (Tg) to the excited state ( e) as dictated hy the transition moment operator. This leads to the absorption band shape shown in (b). 

The magnetic field induces an MCD signal from the g —> e transition that has the absorption band shape. This /i-term is independent of temperature since the ground state is not Zeeman split (i.e., no state to Boltzmann populate) and increases in... 

Eq. (4.28) implies that the absorption band-shape for m -> n is Lorentzian with half-width ynm. In thermal equilibrium, the Boltzmann distributions can be used for and In this case Eq. (4.28) becomes... 

Several physical interaction mechanisms affect optical absorption. Band shapes of polyatomic molecules are broadened relative to the spectral lines of atoms due to shortening of the lifetime of the excited state. This can be due to internal conversion or to isomerization, photodegradation, spin-orbit coupling or excited discrete states. 

B-terms arise from field induced mixing of excited and ground states to other states with Zeeman interaction [10]. States with similar energy are prone to mix more. These transitions have absorption-band shape and are temperature independent. However, if the two mixed states are degenerate in energy, an A-term is observed. When the states are similar in energy then a derivative shaped signal is observed (pseudo A-term) [10]. 

Exciton Absorption Band Shapes and Dynamic Localization of Excitations... 

Ag(Ci) transition, the 205 cm accepting Ag(Ci) absorption band shape. This means that in our particular case the structure represented in Figure 7.4 can be analyzed in terms of the one-dimensional distribution Ji(m5,0 As, Pg). The... 

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