Correction of finite size effects in molecular dynamics applied to the friction coefficient of a Brownian particle Original Research Article

The friction coefficient of a fixed Brownian particle is calculated via an integration of the force-autocorrelation function obtained from molecular dynamics simulation. Due to finite size effects this correlation function decays exponentially to zero, which should not arise in the thermodynamic limit. An efficient way is proposed to overcome the limitation of a finite system and it is demonstrated that it is possible to reach a plateau value in the correlation function integral, which is very close to the friction coefficient determined by different methods.