Electronic structure and properties of neutral, anionic and cationic silicon-nitrogen nanoclusters

We performed a G3 investigation of the possible stable structures of silicon-nitrogen SinNm clusters where m = 1-4, n = 1-4, m + n = 2-5. We considered the neutral, anionic and cationic molecular species in the singlet, doublet and triplet states, as appropriate. For neutral clusters, our data confirm previous DFT and post Hartree-Fock findings. For charged clusters, our results represent predictions. Several molecular properties related to the experimental data, such as the electronic energy, equilibrium geometry, binding energy (BE), HOMO-LUMO gap (HLG), and spin contamination mathematical left angle bracket S₂ mathematical right angle bracket were computed. We also derived the vertical electron attachment (VEA), the adiabatic electron affinity (AEA), and the vertical ionization energy (VIE), of the neutral clusters. Similar to their carbon-nitrogen counterparts, the lowest energy structures for neutral and cationic silicon-nitrogen clusters are found to be linear or quasilinear. In contrast, anionic silicon-nitrogen clusters tend to form 3D structures as the size of the cluster increases.