Relaxation properties in a lattice gas model with asymmetrical particles

We study the relaxation process in a two-dimensional lattice gas model, where the interactions originate from the excluded volume. In this model particles have three arms with an asymmetrical shape, which results in geometrical frustration that inhibits full packing. Relaxation functions are well fitted at long times by a stretched exponential form, with a β exponent decreasing when the density is raised until the percolation transition is reached, and constant for higher densities. The structural arrest of the model seems to happen only at the maximum density of the model, where both the inverse diffusivity and the relaxation times diverge with a power law. The dynamical non-linear susceptibility, defined as the fluctuations of the self-overlap autocorrelation, exhibits a peak at some characteristic time, which also seems to diverge at the maximum density.