Sent to CCL by: "soumya s" [soumya_samineni|a|rediffmail.com] I have generated Al(111) 3X3 surface with slab depth of 4 layers. Can you please suggest me how can i now generate monolayers of additional atoms (like Si) with different surface overages ..? 0.25ML, 0.5 ML and 1 ML . thanx in advace soumya