Memory effects in Brownian dynamics simulations of ion transport

Brownian dynamics simulations of ion transport are often carried out using the Langevin equation with the Markovian assumption for random forces. We investigate whether memory effects play any role in the ion transport processes by comparing the results of simulations obtained using the Langevin and generalized Langevin equations. As expected, the two methods yield similar transport coefficients in bulk simulations but differences appear when ions have to cross potential energy barriers.