The electronic and optical properties of the cleavage InAs(110) surface are studied using a semi-empirical tight-binding method which employs an extended atomic-like basis set. We describe and discuss the electronic character of the surface electronic states and we compare with other theoretical approaches, and with experimental observations. We calculate the surface electronic band structure and the Reflectance Anisotropy Spectrum, which are described and discussed in terms of the surface electronic states and the atomic structure.
