Inhomogeneous Charge Distribution Of Simple Substances

Using density function theory calculation method, we investigated the charge distribution in nano- or low-dimension materials and some high pressure three-dimensional solids in many simple substances. It is found that if an atom in simple substances has different atomic environment from the other(s) nearby, they always have spontaneous charge inhomogeneity within local area. Charge inhomogeneity introduced by inequivalent atomic positions is a general phenomenon in simple substances, especially in their nano-materials. Such self-ionization significantly changes elemental matter's physical and chemical properties. These results can advance the understanding on condensed matters, especially the internal structures and physical or chemical properties of elemental nano-materials, and could be a starting point for experimental investigation of self-ionization in them. The charge inhomogeneity of simple substances means their nonzero oxidation state or nonzero valence.