Abstract
We study the electronic transport characteristics in granular metals. There are three kinds of energy, disorder one-particle energy, charging energy and correlation energy. The single-particle density of states has a Coulomb gap around Fermi level because of the fluctuation in disorder energy and Coulomb interactions. We implement a numerical method to calculate the density of states of granular metal systems. The simulations are based on tight-binding Hamiltonian. The hopping conductivity of a granular metal when the Coulomb gap is present, has the functional form.