Abstract:
The bandwidths of the impurity band in isotopic mixed molecular crystals of C [subscript 10] H[subscript 8] and C[subscript 10] D[subscript 8] in the very low concentration limit is calculated. A continued fraction representation of the self energy of the monomer series is obtained by a selective summing of a series of graphs. The choice of graphs retained was guided by the desire that the singularities of the resulting monomer states lie on the real axis inside a cut. Using the C[subscript 10] D[subscript 8] propagator given by Suporn, the width of the band is calculated and is compared with the CPA results of Hoshen and Jortner.