At each time step of the molecular dynamics simulation, a number of particles are selected to undergo "thermalization". The probability of any given particle being picked in this manner is ν ν Δ Δ t for a (small) time step of length Δ Δ t and coupling strength ν ν , which is a parameter of the simulation. If a particle is picked at some time step, its velocity is changed to a velocity randomly picked from the Boltzmann distribution of velocities. Due to this interaction with a bath, the system conserves neither energy nor momentum. In addition, the velocity autocorrelation function decays more quickly than it would in a real system, due to the random decorrelation of the particles. This effect grows with increasing collision frequency ν ν .