Sutton-Chen potential

Sutton and Chen extended the potential to longer range to enable the study of certain problems such as the interactions between clusters of afoms [Sutton and Chen 1990]. Their objective was to combine the superior Fiimis-Sinclair description of short-range interactions with a van der Waals tail to model the long-range interactions. The form of the Sutton-Chen potential is ... 

In a very general study, Doye and Wales78 optimized all structures for clusters with N up to 80 for more different Sutton-Chen potentials according to which the total energy has the form... 

As a very recent example of theoretical studies of metal clusters with more than one type of atoms we mention the work of Chui and Chan.111 They studied Ptra xCox clusters with n = 500 and x = 125, 250, and 375 and used the semiempirical Sutton-Chen potential together with molecular-dynamics simulation in obtaining the structure. For all systems they could see some effects towards segregation where Pt atoms would form the major parts of the surface region. However, details of the results were strongly dependent on the details of the calculations and of the stoichiometry. 

Several studies have focused on extensive MD simulations of Pt nanoparticles adsorbed on carbon in the presence or absence of ionomers [109-113]. Lamas and Balbuena performed classical molecular dynamics simulations on a simple model for the interface between graphite-supported Pt nanoparticles and hydrated Nation [113]. In MD studies of CLs, the equilibrium shape and structure of Pt clusters are usually simulated using the embedded atom method (EAM). Semi-empirical potentials such as the many-body Sutton-Chen potential (SC) [114] are popular choices for the close-packed metal clusters. Such potential models include the effect of the local electron density to account for many-body terms. The SC potential for Pt-Pt and Pt-C interactions provides a reasonable description of the properties of small Pt clusters. The potential energy in the SC potential is expressed by... 

In an interesting study, Sankaranarayanan et compared bimetallic nanowires with clusters and the macroscopic crystals. They performed molecular-dynamics simulations using the Sutton-Chen potential for an approximate description of the interatomic interactions. They considered two systems, Pd-Rh and Pd-Cu. As initial structures, they considered cut-outs of the infinite, crystalline fee or hep structures. Subsequently, the two types of atoms were distributed at those atomic positions that led to the... 

Joswig, J.-O., 8c Springborg, M. (2003). A genetic-algorithms search for global minima of aluminum clusters using a Sutton-Chen potential. Physical Review B, 68, 085408. 

J. P. K. Doye and D. J. Wales. Global minima for transition metal clusters described by Sutton-Chen potentials. New J. Chem. 22, 1998,733-744. 

Many body potentials e.g. Sutton-Chen, Tersoff, " Brenner can be used to describe metals and other continuous solids such as silicon and carbon. The Brenner potential has been particularly successful with fullerenes, carbon nanotubes and diamond. Erhart and Albe have derived an analytical potential based on Brenner s work for carbon, silicon and silicon carbide. The Brenner and Tersolf potentials are examples of bond order potentials. These express the local binding energy between any pair of atoms/ions as the sum of a repulsive term and an attractive term that depends on the bond order between the two atoms. Because the bond order depends on the other neighbours of the two atoms, this apparently two-body potential is in fact many-body. An introduction and history of such potentials has recently been given by Finnis in an issue of Progress in Materials Science dedicated to David Pettifor. For a study of solid and liquid MgO Tangney and Scandolo derived a many body potential for ionic systems. 

For the MC calculations, Sutton-Chen multi-atomic potential is applied with an annealing method to simulate the pseudo-equilibrium atomic repartition of each stracture. This potential provides the total nanoparticle energy Uas the addition of terms that describes the two-body repulsive interaction between the atoms / and... 

In MD modeling, the molecular adsorption concept is used to interpret the Pt-C interactions during the fabrication processes. The Pt complexes are mostly attached to the hydrophilic sites on the carbon particles, viz. carbonyl or hydroxyl groups (Hao et ah, 2003). The adsorption is based on both the physical and chemical adsorptions. Many efforts have been done on the MD simulations of Pt nano-particles adsorbed on carbon with or without ionomers (Balbuena et ah, 2005 Chen and Chan, 2005 Huang and Balbuena, 2002 Lamas and Balbuena, 2003 2006). The Pt-Pt interactions are modeled with the many-body Sutton-Chen (SC) potential (Rafii-Tabar et al, 2006), whereas a Lennard-Jones (LJ) potential is used to describe the Pt-C interactions. The SC potential for Pt-Pt and Pt-C interactions provides a reasonable description of the properties for small Pt clusters. The diffusion of platinum nano-particles on graphite has also been investigated, with diffusion coefficients in the order of 10 cm s (Morrow and Striolo, 2007). 

With the EAM, the total-energy expression of O Eq. 26.8 contains also contributions from P-body interactions with P being the number of nearest neighbors of the atoms of the system of interest. Other potentials that also include many-body interactions are the Gupta, Murrell-Mottram, Sutton-Chen, and Cleri-Rosato potentials. Since we have used the Gupta, Sutton-Chen, and Cleri-Rosato potentials in some studies we shall here discuss these briefly. 

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

Sutton A P and J Chen 1990. Long-range Finnis-Sinclair Potentials. Philosophical Magazine Letters 61 139-146. 

Sutton AP, Chen J. Long-range Finnis-Sinclair potentials. Philos Mag Lett 1990 61(3) 139-46. 

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