Ab initio absorption spectra of CdSe clusters -: art. no. 033311

Ab initio absorption spectra for CdnSen clusters (1less than or equal tonless than or equal to8) are calculated using an adiabatic time-dependent density functional formalism within the local density approximation (LDA). We find that the calculated spectra differ significantly from those computed using a simple LDA approach. In particular, they correct for the well-known underestimate of the absorption gap in time-independent density functional theory. The calculated spectra exhibit a variety of features that can be used for comparison against future experimental investigations. In addition, we find a correlation between the highest occupied molecular orbital-lowest unoccupied molecular orbital gap, the optical gap, and the cluster binding energy.