Density of states and energetic correlation in disordered molecular systems due to induced dipoles.

We have considered two models for a system of disordered organic molecules: one based on a regular lattice with Gaussian site displacements and another based on a hard sphere distribution. The site energies were given by a charge-induced dipole interaction (the polarization energy). We obtained the density of states of both models and observed that it changes from a Gaussian to the density of states of a uniform site distribution, whose form was obtained analytically, depending on the degree of disorder in one model or the packing fraction in the other model. The site energy distribution is short-ranged correlated in both models since nearby molecules polarize basically the same disordered environment.