Calculation of electronic structure of TCNQ molecule by self-consistent statistical-exchange multiple-scattering method

The electronic structure of the TCNQ molecule has been determined by the self-consistent statistical-exchange multiple-scattering method. The calculation is based on an overlapping-atomic-sphere model in which the nonoverlapping atomic spheres are uniformly scaled so that the calculated virial ratio is equal to -2. This model can be further improved by adjusting the outer-sphere radius so that the first theoretical and experimental ionization energies are in registry. A realistic energy level structure is obtained for the higher occupied and lower excited levels. The present approach appears capable of dealing with large organic molecules as well as arrays of such molecules, including dimers, trimers and charge transfer complexes. © 1974 Società Italiana di Fisica.