AL DIMER DYNAMICS ON AL(111)

Al dimer dynamics on Al(111) at equilibrium and under compression is s tudied using first-principles density-functional theory calculations. A smooth potential energy surface provides a long-range attraction bet ween the dimer atoms and leads to a substantial temperature window in which dissociation is frozen and exotic dimer dynamics is observed. Su rface relaxations play a prominent role in the uncovering of an unexpe cted ground state and a new diffusion path. A way of affecting growth by compression is illustrated. The possibility of a metal quantum roto r is addressed and further examined using effective-medium theory calc ulations.