https://doi.org/10.1007/s100530050334
Ground-state geometries and stability of NanMgn=1‒12 clusters using ab initio molecular dynamics method
1
Department of Physics, University of Pune, Pune 411 007, India
2
Chemistry Division, Bhabha Atomic Research Center, Mumbai-400 085, India
3
Solid State Physics Division, Bhabha Atomic Research Center, Mumbai-400 085, India
Received:
16
September
1998
Revised:
15
February
1999
Published online: 15 July 1999
The ground-state geometries, energetics and the stability of
clusters are studied using
ab initio molecular dynamics method. Our results
indicate that the ground-state geometries of large clusters
(
) are different from those of
clusters where a trivalent impurity
Al is added to the same monovalent host Na.
Other features observed are an early appearance of 3-dimensional structure
and a pentagonal growth path from n=6 up to n=11.
As expected, the ground-state geometry of
is not an icosahedron but can be
viewed as a distorted form of one of the low lying geometries of
cluster. In the energetically favored structures
impurity atom Mg is never located at the
center of the cluster. The stability
analysis based on the energetics shows
(8 valence electrons) to be the most stable.
In addition there is a remarkable even-odd pattern observed in the
dissociation energy and the second difference in energy which is absent
in earlier studies of
and
clusters.
PACS: 36.40.Qv – Stability and fragmentation of clusters / 36.40.Mr – Spectroscopy and geometrical structure of clusters / 61.46.+w – Clusters, nanoparticles, and nanocrystalline materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999