Pairwise Model Potential and DFT Study of Clusters ( = 1-20): The Structural, Electronic, and Thermodynamic Properties.

The structural properties, relative stabilities, electronic, and thermodynamic properties, of ( = 1-20) clusters have been studied based on a pairwise model and density functional theory () methods. In the pairwise method, the potential energy surface considered interactions between , - , and many-body term. For the calculations, the 3 functional combined with the 6-311 + + (2,2) basis sets has been employed. In both methods, the cluster demonstrated high stability with an octahedral structure, where the cation was surrounded by atoms. Thus, the octahedral structure was considered to be the core for larger cluster sizes. Relative stabilities were assessed based on binding energies, second-order differences of energies, transition dipole moment, and HOMO-LUMO energy gaps. Furthermore, thermodynamic properties were calculated, revealing that the formation process of clusters is endothermic and nonspontaneous.