The behavior of a solvated electron in an electrolyte is investigated. The
formalism of the theory is based on variational estimation of path integral
s. It reduces the problem to the investigation of the self-consistent mean
field produced by the ions and the electron. Mayer cluster expansions make
it possible to take account of the short-range interactions and to find exp
ressions for the effective potential of the electron and the electron-ion a
nd electron-neutral atom correlation functions as a function of the macro-
and microscopic parameters of electrolytes. In the limit of high ion densit
ies the behavior of the electron is determined solely by the Coulomb intera
ction, which results in the formation of a polaron state. This state of the
electron is virtually independent of the thermodynamic parameters of the e
lectrolyte. In the opposite limit of low ion densities the electron forms a
cavity state. The presence of ions results in additional localization of t
he electron and is manifested experimentally as a shift of the absorption b
and in the direction of high energies. The estimated shift for a hydrated e
lectron agrees with the experimental data. (C) 1999 American Institute of P
hysics. [S1063-7761(99)02104-6].