Abstract
Crystal growth in molecular-beam-epitaxy conditions on misoriented surfaces is described with a nonlinear model. Adsorbed atoms may annihilate through collisions with adatoms and existing clusters. Clusters grow only by attachment of single atoms. The conditions under which step flow dominates are displayed as a function of the growth parameters. The cluster density is of the same order or larger than the adatom density. Medium-sized clusters of about 10 atoms will be important also in the conditions most favorable for two-dimensional growth.