A local model based on the discrete dipole model has been developed in order to treat internal field effects at the surface of dielectric systems. The central part of the model is the double cell technique in which we match a freely chosen surface layer to the underlying bulk described by normal modes. We calculate the bulk and surface contributions to the anisotropic reflectance of the (1 1 0) surface of GaP obtaining results as good as the best delocalised treatments.
Poppe, G. P. M., Poppe, G. P. M., Wijers, C. M. J., & van Silfhout, A. (1991). The double cell technique: a discrete dipole approach towards surface optics. Solid state communications, 0(78), 773-777. https://doi.org/10.1016/0038-1098(91)90862-P