Although pure DFT methods yielded the smallest deviations from the crystal structure, their steep computational scaling limits routine application for large-scale system size. On the other hand, the ONIOM(DFT//xTB) combined approach can be orders of magnitude faster, depending on the size of the inner region, and offers better accuracy than the underlying xTB low-level theories alone. As a result, the ONIOM framework can be expected to achieve a more balanced cost-efficiency ratio compared to standalone methods.