By using reflection high-energy electron diffraction (RHEED) and RHEED mult
islice dynamical calculations, the atomic structures of the (root3 x root3)
R30 degrees reconstruction on 6H-SiC(0001) surface were solved. Both the si
mple adatom structure with a Si coverage of one-third monolayer occupying t
he threefold-symmetric T-4 or H-3 sites and a bit complex structure with Si
trimers centered on the T-4 positions with 1 monolayer coverage are all co
mpatible with our results. (C) 2001 American Vacuum Society.