An atom-atom Lennard-Jones (LJ) model for the intermolecular potential of carborane molecules (B10C2H12) is developed and used in a series of classical constant-pressure molecular dynamics simulations of p-, m- and o-carborane crystals, at several temperatures and zero pressure. The potential model reproduces many structural and dynamical properties of these crystals, in particular the high temperature orientationally disordered plastic phase common to the three compounds. This work stresses the need of further experimental data to improve the potential model.