Interatomic pair potentials

Ghrayeb R, Purushotham M, Hou M and Bauer E 1987 Estimate of repulsive interatomic pair potentials by low-energy alkalimetal-ion scattering and computer simulation Phys. Rev. B 36 7364-70... 

The interatomic pair potential ( 0) in eqn (6.73) represents the electrostatic interaction between an ion and a second ion and its screening cloud some distance, R, away. From eqn (6.71) it is given by... 

Fig. 6.7 Interatomic pair potentials for (a) Na, (b) Mg, and (c) Al as a function of the interatomic separation in units of the Wigner-Seitz radius / ws. The positions of the fee first and bcc first and second nearest neighbours are marked. Since fee and ideal hep structures have identical first and second nearest neighbours, their relative structural stability is determined by the more distant neighbours marked in the figures. (After McMahan and Moriarty (1983).)...

The atomistic approach to modelling the crystal structure and properties involves the definition of interatomic potential functions to simulate the forces acting between ions. As discussed in Chapter 1, interatomic pair potentials can be written as ... 

Figure 12. The phonon spectrum for stishovite calculated at ambient pressure from interatomic pair potential calculations. The solid circles are from experiment.

Chapter 11 deals with the tight-binding and the embedded-atom models of solid state. The method of the local combination of atomic orbitals is described. We present examples of the technique application. Description of atom systems in the embedded-atom method, embedding functions and applications are considered. In conclusion the reader will find the review of interatomic pair potentials. 

Four classical interatomic pair potentials are widely used to describe solid states. Various crystal properties can be expressed in terms of the Morse potential Um The pair interatomic potential of Morse is expressed as... 

There are three approximate theories of the liquid state in frequent use (see, for example, Enderby and March (1965)). Their common feature is that they attempt to relate the radial distribution function g(r) to the interatomic pair potential 0(r). For convenience we list the theories and the relevant equations below as applied to a pure liquid. The generalisation to include multi-component liquids is straightforward Percus-Yevick (PY) ... 

Owing to the short-range nature of the interatomic pair potential, the non-stationary part of the atom-surface interaction is 2tssumed to be maunly contributed by the first layer of surface atoms. The instant configuration of this layer is described by the displacement Uk of kth atom from its equihbrium position Rk. It is convenient to express Uk through the amplitudes at of phonon modes I = (q,j) with wave vectors g and polarizations j (the system of units with ft = 1 is used throughout this review) ... 

Atomistic calculations based on an interatomic pair potential within the sheU model approach [19]. 

To examine the effects of anharmonicity on the decay of excited clusters, calculations were performed for hot clusters in which the alternate, truncated harmonic potential, equations (7) and (8), was employed as the atomic pair potential. While the interatomic pair potential was harmonic in form, the entire cluster was not a harmonic system since displacements along the normal mode coordinate were not subject to restoring forces which were linear functions solely of the displacements along those coordinates. The change in potential nonetheless causes a change in the density of states for the cluster. 

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