Photodetachment Spectra of Trapped Electrons in Spherical Potentials

The line shapes of absorption spectra of trapped electrons in metal-ammonia solutions, water, and alcohols are compared in detail with photodetachment spectra of spherical potentials, which have been applied extensively in liquid helium. A qualitative discussion is presented to point out some uncertainty in the role of the bound-bound transition $1s\to 2p$, which is predominant in the dielectric continuum model. Apart from the uncertainty related to the effective mass of the polaron, the coherence of the $2p$ state in the more realistic fluctuation potential is likely to be small. A molecular model for the trapped electrons is briefly described.