Similarly, the endo-N Ni 2 L 4 metallacage demonstrated the second-lowest energy, with a value of -4171.0974 Hartree, suggesting it is also relatively stable. Unfortunately, the endo-C Pt 2 L 4 and endo-C Pd 2 L 4 complexes exhibited higher energy levels, -4004.0314 and -4019.187 Hartree, respectively, indicating that these cages are less stable and further from their ground-state energy. This trend aligns with earlier assessments, reinforcing that the Pt 2 L 4 and Pd 2 L 4 cages may be less favourable for cisplatin encapsulation due to their relatively higher energies and reduced stability. Geometry Optimisation for Encapsulation of Single Cisplatin Molecule Table shows the outputs of the geometry optimization. While the Hartree Fock method did not complete the optimization for both Cu 2 L 4 metallacages, the better PBE0/LanL2DZ method successfully provided results for metallacages. Consequently, this discrepancy highlights the enhanced accuracy of hybrid functionals like PBE0 over Hartree Fock, which is crucial for obtaining reliable energy assessments. the energy values obtained after geometry optimization of various cage-cisplatin complexes using two computational methods: Hartree-Fock with the LanL2DZ basis set and PBE0 with the LanL2DZ basis set. The energy differences between these methods are highlighted to demonstrate how each cage structure, depending on the metal centre (Pd, Pt, Ni, Cu, Au) and encapsulation mode (Endo-N or Endo-C), affects the overall energy stability of the complex. The results also indicate instances where the calculations failed for certain structures.