A wave operator description of molecularphotodissociation processes using the

During the last few years the Floquet matrix approach to the theory of intense-eld multiphoton dissociation processes has undergone 1 a revival of interest which is due to the emergence of new powerful algorithms within the complex quasivibrational energy formalism. The method presented here shows that the Bloch wave operator theory is, in the framework of this theory, an eecient tool to select the active space which principally participates in the dissociation process. An illustrative numerical example reveals that the one dimensional active space model, mainly used to reproduce c.w. laser experimental results fails when the laser is tuned to bound state-bound state transitions.