All grand canonical Monte Carlo (GCMC) simulations were carried out in the AMS-ReaxFF implementation of the Amsterdam Modeling Suite 2021.1 . The chemical potential µ was referenced to the cohesive energy of the respective metal using a simulation temperature of 300 K. Also, an µVT ensemble was chosen for all GCMC simulations. A minimum distance of 1.0 Å and a maximum distance of 3.0 Å to the other atoms of the system were set as boundary conditions for adding an atom. The accessible volume was determined by the difference between the total and occupied volumes.