Ms. Deshpande et al., EFFECTIVE-MEDIUM THEORY FOR THE NORMAL-STATE IN ORIENTATIONALLY DISORDERED FULLERIDES, Physical review letters, 71(16), 1993, pp. 2619-2622
An effective medium theory for studying the electronic structure of th
e orientationally disordered M3C60 fullerides is developed and applied
to study various normal state properties. The theory is based on a cl
uster-Bethe-lattice method in which the disordered medium is modeled b
y a three-band Bethe lattice, into which we embed a molecular cluster
whose scattering properties are treated exactly. Various single-partic
le properties and the frequency-dependent conductivity are calculated
in this model, and comparison is made with numerical calculations for
disordered lattices, and with experiment.