Fig. 7: Schematic of alternating terraces and steps for the BCF model.
From: In situ microbeam surface X-ray scattering reveals alternating step kinetics during crystal growth

Vicinal {0001} surfaces of HCP crystals have alternating α and β terraces separated by A and B steps. Notations are indicated for the kinetic coefficients for adatom attachment from below and above and for adatom transmission. Schematic of alternating terraces and steps of BCF model for HCP basal-plane surfaces, showing kinetic coefficients for the A and B steps.