Calculation of Surface Distortion in an Alkali Halide Crystal Bounded by a Free {100} Face

Previous calculations of the distortion in the outermost layer at a {100} face of an alkali halide hemicrystal with NaCl-type structure are extended to consider deformations occurring within the first n layers. The model permits the ions of the surface region to relax in a direction normal to the face and to be polarized by the local electric field; the equilibrium configuration is determined by minimizing the energy of the system. Results of numerical computations with n = 5 are presented for a number of alkali halides.