Modeling of the deposition of Na Clusters on MgO(001)

Abstract

We investigate the dynamics of deposition of small Na clusters on MgO͑001͒ surface. A hierarchical modeling is used combining quantum mechanical with molecular mechanical description. Full time-dependent density-functional theory is used for the cluster electrons while the substrate atoms are treated at a classical level. We consider Na 6 and Na 8 at various impact energies. We analyze the dependence on cluster geometry, trends with impact energy, and energy balance. We compare the results with deposit on the much softer Ar͑001͒ surface.

Orientation averaged angular distributions of photo-electrons from free Na clusters

“…They also allow to describe correctly electron emission by employing absorbing boundary conditions [24,25] and a careful bookkeeping delivers a convenient TDLDA evaluation of PAD [26,27] without the need of constructing explicitly the cumbersome outgoing states. This procedure is simple for molecules/clusters with fixed orientation.…”

“…High quality PAD are obtained by using spherical bounds with a radially symmetric mask function M(| r|) [27]. The mask is active only in the absorbing zone R cut | r| R box (with 2R cut = 72a 0 , 2R box = 76.8a 0 ) near the bounds of the numerical box and it switches gently from 1 to 0 to minimize unwanted reflections [31].…”

Frequency dependence of photoelectron angular distributions in small Na clusters

“…This is appropriate when considering clusters deposited on a substrate [21]. However, most PAD measurements deal with an ensemble of free, randomly orientated clusters.…”