July 31 2003
Average shape of constructed ih cluster with 5082 gold atoms
Construction of ideal ih cluster with 5082 gold atoms
A program has been written to build the Mackay icosahedral gold clusters.
According to the cooling results of 2624-atom cluster, the central atom has
been carried out. The ih cluster with 11 layers has 5082 atoms (excluding
the central one).
The average potential energy has been calculated versus the minimum
distance among atoms. It has been found that the distance with minimum
energy is about 2.9 Angstrom.
Average shape at different temperatures
The above constructed cluster has been relaxed at T=5K and equilibrated at
T=800K with constant T MD for 4.3ns (10^6 steps). After that, it has been
equilibrated at 900, 1000, 1100, 1200, 1300 and 1400K step by step. The
system melted at 1200K.
The average shape has been calculated with the last 100 configurations
from the overall 120 configurations at each temperature. When calculating
the average shape, instead of the previously used solid angle method, we
divide the solid angle according to
the spherical codes with icosahedral symmetry developed by
R. H. Hardin et al. The best covering method with 1212 points have been used
because there are 1212 surface atoms at T=5K.
Icosahedral symmetry with 1212 points
Standard deviation of the average shapes
Average shape in 3D
| T |
3D average shape |
| 800K |
 |
| 900K |
 |
| 1000K |
 |
| 1100K |
 |
| 1200K |
 |
| 1300K |
 |
| 1400K |
 |