We extend work of Friedberg and Luttinger on the density of low-lying electronic levels of a disordered system. Previously, we considered only uncorrelated scattering centers and now we consider correlations between them. The Lifshitz term and the first correction to it are obtained. When the scatterers may be described as a fluid in equilibrium, the final result can be expressed purely thermodynamically.
- Received 28 October 1975
- Published in the issue dated 15 March 1976
© 1976 The American Physical Society