The results of the SCF-LCAO-MO calculations for the electronic structure of carbazole and trinitrofluorenone are reported. Comparison is made with previous computations and with experimental data. A qualitative calculation tends to explain satisfactorily the first electro-absorption peak in amorphous films of polyvinylcarbazole and trinitrofluorenone on the basis of a complete charge transfer model. The singlet-triplet splitting predicted for carbazole also compares favorably with the experimental results. © 1974 Springer-Verlag.