On the influence of non-nearest neighbor interactions and anharmonicity on the atomic properties of a crystal surface: One-dimensional model

We describe self-consistently the effects of non-nearest neighbor interactions and anharmonicity on the atomic properties of a crystal surface. An approach is developed based on the unsymmetrized self-consistent field approximation (USF). The structural, dynamical and thermodynamic properties of a semi-infinite linear chain are studied in the classical limit. Expressions for the lattice relaxation in the vicinity of the surface, the mean-squared atomic displacements and for the surface energy and free energy are obtained. Quantitative estimates were made using the Lennard-Jones 6-12 interatomic potential.