The computation of stationary optical spectra of mol. systems based on a wavepacket propagation on excited potential energy surfaces (PES) is extended to the condensed phase case in utilizing the d. matrix theory. As an example, a one-dimensional model is studied for the photodissocn. of matrix isolated HCl. Emphasis is put on the interplay of the cage effect and the energy dissipation into the matrix. [on SciFinder (R)]