Density functional investigation of metal encapsulated X@C ₁₂Si₈ heterofullerene (X=Li⁺, Na⁺, K⁺, Be²⁺, Mg²⁺, Ca²⁺, Al ³⁺, Ga³⁺)

The stability and the possible application of our recently reported SiC heterofullerenes inspire the investigation of their further stabilization through ion encapsulation. The endohedral complexes X@C₁₂Si ₈, where X=Li⁺, Na⁺, K⁺, Be ²⁺, Mg²⁺, Ca²⁺, Al³⁺, and Ga ³, are probed at the MPWB1K/6-311G and B3LYP/6-311G (*) levels of theory. The optimized geometries show the expanding or contracting capability of C₁₂Si₈ in order to accommodate metal ion guests. The inclusion energies indicate the stability of the complexes compared to the components. Meanwhile, the calculated binding energies show the stabilization of C₁₂Si₈ through the inclusion of Be²⁺, Mg ²⁺, Al³⁺, and Ga³⁺. The hostguest interaction that is probed through NBO atomic charges supports the obtained results. This study refers to "metal ion encapsulation" as a strategy for stabilization of SiC heterofullerenes.