Quantum mechanical methods such as Hartree-Fock (HF), configuration interaction (CI), Coupled Cluster (CC) or density functional theory (DFT) are powerful tools to study the electronic properties of molecular structures or solid-state systems. However, due to their high computational cost, these methods are limited to short simulation times and small systems with a few hundred atoms. The bond order based reactive force field (ReaxFF) approach overcomes these limitations and enables large scale (up to 100.000 atoms), longterm (∼ ns), fully reactive simulations for complex systems. The accuracy of the force field potential depends heavily on the scope and quality of the chosen training and validation set. Within the force field development process, many physical and empirical parameters (in some cases hundreds) have to be fitted to ab initio quantum chemical or experimental reference data. Pre-existing correlations between the parameters and discontinuities in the error function further aggravate the optimisation task . Identifying the local optima of this multimodal optimisation problem is a substantial challenge and, in most cases, only feasible with a deep, chemical understanding of the underlying formalism.