Abstract
Atomistic growth mechanisms for the molecular-beam epitaxy of a Lennard-Jones crystal are investigated by a quantitative comparison of a numerical molecular-dynamics simulation with kinetic analytic theories. We find that the growth mechanism along the (100) and (111) surfaces changes from low-temperature growth involving two-dimensional cluster nucleation on terraces to a high-temperature continuous step-propagation mechanism. This crossover in growth mechanism is found to be kinetically controlled.