HSE-level SPE calculations using PBE0optimised structures as input suggested the heteroleptic cage should be favoured (ΔEhet = 12.1 kJ mol -1 ), consistent with experimental results. Conversely, using HSE-optimised structures led to a negligible difference in the SPEs of the homo-and heteroleptic systems (ΔEhet = 0.4 kJ mol -1 ). Once again, using the SCXRD of the homoleptic [Pd2(2 Py )4] 4+ as initial input before geometry optimisation caused the SPE calculations to indicate the homoleptic species were thermodynamically favoured (ΔEhet = -7.5 kJ mol -1 ), albeit by a small amount (Table ).