where k push controls the strength of the biasing potential, defining how strongly the system should be 'pushed' out of previously visited structures. Choosing too small a value, we approach the unbiased MD limit where no reactions take place (or at least unreasonable long simulations are needed for them to occur). On the other hand, choosing too high a value can lead to chemically irrelevant reactions. n is the number of structures saved (which the system is pushed out of). Here, a new structure is added to the biasing potential every picosecond. ∆ i is the root mean squared deviation (RMSD) between the current structure and structure i in Cartesian space. α describes the width of the biasing potential and thus determines how far from the saved structures the system is still affected by the biasing potential. A high value of α prescribes a narrow biasing potential meaning that the system can 'escape' the biasing potential by smaller changes to the structure (e.g. conformational changes). A low value of α means that very large changes in the structure are needed to avoid being affected by the biasing potential.