Growth morphology of hexagonal crystal and the corresponding atomic density maps for the parts enclosed by dashed boxes simulated with parameter n̄ = −0.462 at different times: (a) and (e) t = 1600, (b) and (f) t = 4000, (c) and (g) t = 20000, and (d) and (h) t = 63000. The white lines in panels (e) and (f) outline the newly generated layers. The color bar in the top row represents the variation of the smoothed atomic density field n_smooth.