Potential Gupta

Figure 4 Ground state geometries of Ni clusters with 5 to 16 atoms (symmetries are indicated), obtained using the Gupta potential. Reproduced with permission from Ref. 45.

Metallic clusters were studied by Lai et al. [85] employing Gupta potentials for lead and the alkali metals, and their EA approach was compared with the basinhopping method. Pastor and Poteau [20] used EA methods on a generic TB level, for smaller clusters up to n=13, with an adjacency matrix encoding, tests of several crossover schemes, and seeding with the best structures of smaller n-1 clusters. 

These issues were addressed in mixed-cluster studies for <56 with Gupta potentials, for the systems Pd/Pt [92] and Cu/Au [93]. Segregation tendencies were found, and a surprisingly strong dependence of structure on composition, with qualitative changes of cluster structure upon addition of a single different atom. 

Figure 17 Variation in the total energy for NaN clusters as found with (upper panel) the Gupta potential and (lower panel) the Murrell-Mottram potential. Local minima correspond to particularly stable clusters. Reproduced with permission from 69...

On the other hand, Michaelian et al.sl studied the structures of some few selected clusters of Ni, Ag, and Au using the Gupta potential. 

In another study, Lai et al 9 studied the structures of clusters of various metals. In describing the interatomic interactions they used the Gupta potential.76 According to this, the total energy is written as... 

Fig. 36 The similarity functions obtained when comparing the global total-energy-minima structures for the Ag clusters with those of Cu y, Nijv, and Au y clusters, as well as when comparing the two different Gupta potentials for the Agjv clusters. Reproduced with permission of American Chemical Society from ref 112.

With the Gupta potential (Gupta 1981), the total energy is written in terms of repulsive and attractive many-body terms,... 

As for the Gupta potential, the values of the parameters that enter the Sutton-Chen and Cleri-Rosato potentials are determined from experimental information. 

To understand their behavior at finite temperature, Wu and coworkers studied Zn clusters using the Gupta potential by means of molecular dynamics (Wu et al. 2005). Zn clusters are found to display peculiar structures that are very different from other sp-type metal clusters. The AT = 13 cluster, for instance, has a disordered structure instead of the icosahedral structure found in most metals of the same size. The Cy curve also differs in that it has a double... 

An interesting result from the work of Doye (2006) is that for the Gupta potential the uncentered Mackay icosahedron with N = 54 is more stable than the complete N = 55 Mackay icosahedron. This is because of the strain applied by the external atoms on the center, making it unfavorable to be occupied. 

---