The GCMC approach 108,109 is a stochastic method for studying the thermodynamic equilibrium structures at a given chemical potential µ. A series of Monte Carlo trial moves are carried out by the GCMC algorithm and accepted or rejected based on the minimum energy of the trial geometry. Each trial movement entails either the addition (insert), removal (remove) or displacement (move) of a particle. The Boltzmann probabilities P for accepting the respective MC steps are calculated by