Computer simulation of diffusion coefficients of the room-temperature ionic liquid [bmim][BF4]: Problems with classical simulation techniques

In this work, we present a computer simulation study of the translational diffusion of the room-temperature ionic liquid [bmim][BF4]. Molecular dynamics simulations have been used, employing a recently developed classical, non-polarizable force field. We compare the results of the simulation with experimental data obtained by NMR spectroscopy and discuss some shortcomings of the simulations. The strong underestimation of calculated diffusion coefficients is traced to artefacts in the simulation and deficiencies in non-polarizable force fields.