The Occurrence of Non-Gaussian Spectral Line Shapes of Molecules in Electrostatically Disordered Media

We calc. the effects of relatively strong elec. fields, corresponding to typical values for the fields inside glasses and proteins, on the spectroscopic properties of a simple two-level mol. Disorder in the elec. field strength is employed as a phys. source for inhomogeneous broadening. A striking result is that a Gaussian probability distribution for the field over the ensemble does not give rise to a Gaussian spectral line shape. The results are used to describe the absorption spectra of the B800 band of the B800-850 light-harvesting complex of photosynthetic purple bacteria. [on SciFinder (R)]