Langevin molecular dynamics were used to directly simulate the diffusion, D(t), of charged particles in structurally disordered lattices, as a first step to study the non-Debye behaviour in this type of system. This method was an alternative to Monte Carlo simulation, but without the artificial time step inherent in this scheme. A 3D many-particle system was simulated in the canonical ensemble via a Langevin approach. Long-range Coulomb interaction between particles was considered as well as a quasi-periodic substrate potential to mimic the disordered lattice. The results showed that a dispersive regime, D(t)∼β-1, appeared at length scales of the particle jumps. Thermal variations of β values were performed and indicated a similar behaviour to MC simulations.

Study of the Diffusion in Disordered Ionic Conductors by Langevin Molecular Dynamics. Puértolas, J.A., Falo, F.: Journal of Non-Crystalline Solids, 1994, 172-174[2], 1202-6