Electronic excitation energies of Zn(i)S(i) nanoparticles

The excitation energies of small ZnS nanoclusters characterized in previous studies have been calculated using TDDFT. The relativistic pseudopotentials of Stevens et al have been used, including Zn 4s(2) electrons and S 3s(2) and 3p(4) electrons as valence electrons. Results obtained with these pseudopotentials are compared to those obtained considering also Zn 3s(2)3p(6)3d(10) electrons in the valence part, and demonstrated to be consistent. The results show that spheroid-like bubble structures have absorption energies in the range of 5-5.3 eV for small sizes, which decreases to 5 eV with increasing particle size.