Electronic states in topologically disordered systems

Networks generated from Voronoi tessellations of space are prototypes for t opologically disordered systems. In order to assess the effects of random c oordination on the statistical properties of energy spectra, we analyze tig ht-binding models for planar topologically disordered systems. To this end, the networks are generated by a simple topological model covering a wide r ange of naturally observed random structures. We find that the energy-level -spacing distributions exhibit level repulsion, similar to the spacings in the energetically disordered Anderson model of localization in the metallic regime.