  We study the electronic structure of Bi(2)Se(3) employing high resolution
photoemission spectroscopy and discover the dependence of the behavior of Dirac
particles on surface terminations. The Dirac cone apex appears at different
energies and exhibits contrasting shift on Bi and Se terminated surface with
complex time dependence emerging from subtle adsorbed oxygen-surface atom
interactions. These results uncover the surface states behavior of real systems
possessing topologically ordered surface.
