Symmetry effects in reversible random sequential adsorption on a triangular lattice

Reversible random sequential adsorption of objects of various shapes on a two-dimensional triangular lattice is studied numerically by means of Monte Carlo simulations. The growth of the coverage ρ(t) above the jamming limit to its steady-state value ρ_∞ is described by a pattern ρ(t)=ρ_∞-ΔρE_β[-(t∕τ)^β], where E_β denotes the Mittag-Leffler function of order β∊(0,1). The parameter τ is found to decay with the desorption probability P_- according to a power law τ=AP_-^-γ. The exponent γ is the same for all shapes, γ=1.29±0.01, but the parameter A depends only on the order of symmetry axis of the shape. Finally, we present the possible relevance of the model to the compaction of granular objects of various shapes.