Ab initio absorption spectra of Aln (n=2-13) clusters -: art. no. 035428

We investigate the optical absorption spectra of Al-n (n = 2 - 13) clusters using the time-dependent spin-polarized local-density approximation. The overall shapes of the calculated spectra strongly depend on cluster geometries. It is observed that a simple jellium model is not valid for these clusters. In the size range of n less than or equal to 5, the spectra show discrete, atomiclike transitions. For n = 6-12, the shape of the absorption spectra can be explained on the basis of an ellipsoidal shell model. A strong collective excitation peak is observed for Al-13 cluster, which is due to its spherical symmetry.