Browsing by Author "Wiles, G G"

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    The effect of lattice periodicity on the electronic configuration near a metal surface
    (1976) Andriotis, Antonios N; Wiles, G G; Frahn, W E
    A method is developed for calculating single electron wave functions in a semi-infinite metal. The effect of the lattice periodicity is explicitly taken into account so that the solution in the far interior is consistent with the band structure of the infinite crystal. The solution is sufficiently general to include surface states. The single electron potentials are reconsidered and some new features are discussed. These include the elimination of the singular zero-order Fourier terms of the ion-electron and Hartree potentials which leads to the surface dipole barrier. Also a simple formula is derived for the exchange potential in the zero-order approximation which allows to calculate the exchange potential for wave vectors which have components of velocity parallel to the surface. The method is finally applied to a semi-infinite sodium crystal with a (001) orientation.
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    A molecular dynamics investigation of a free surface of liquid argon
    (1974) Opitz, Azel Carl Louis; Wiles, G G; Frahn, W E
    A molecular dynamics simulation technique is employed to investigate the equilibrium molecular structure of the liquid-vapour interfacial region for argon at about 124 °K. The density profile through the surface is found to be of a non-monotonic form. The pair distribution function in the surface is also determined and compared to radial distribution functions of the interior liquid. The surface tension and surface energy are also obtained and are found to be in agreement with generally accepted experimental values.