Geometry relaxation in the excited states and its effects on the electronic properties of the Er(8-hydroxyquinolate)3 complex

We present the results of a semiempirical study of the geometry relaxation effects on the electronic properties of the Er(8-hydroxyquinolinate)3 complex, chosen as a model system in which energy transfer takes place. Geometry distortion in the excited states can affect several photophysical properties such as Stokes shifts, emission in target regions of the spectrum, lifetimes and others. In spite of this fact, in the majority of the theoretical works geometry rearrangements induced by photon absorption are simply ignored, due also to practical difficulties connected to the size of the complexes.