In this paper we present a theoretical study of the physical properties of solvated electrons in ammonia based on the Copeland-Kestner-Jortner model, which incorporates short-range interactions via a first solvation layer and long-range interactions via polaron modes. We have studied bound-bound and bound-continuum optical transition emphasizing the problem of line shapes in absorption and emission. The total energy of the ground and excited states and its dependence on nuclear configurations was handled by three successive approximate calculations: (a) a temperature dependent potential including short-range radial displacements; (b) a temperature independent potential incorporating both radial and angular short-range displacements; (c) a multidimensional potential surface including both short-range and long-range (polaron) nuclear displacements. The calculated line shapes in absorption for a single solvent configuration include major contributions from short-range radial displacements and from the polaron modes. The energy and line shape for the 2p →1s emission band is predicted. A general formula is presented for photoionization cross section including the contribution of all medium modes and in this case the role of the polaron modes is crucial.