The visible-near-IR absorption spectra of a bis(TTF) molecule, 4,8-diethoxy-2,7-bis(benzo-1’,3’-dithiol-2’ylidene)-1,3,5,7-tetrathia-s-indacene (1), and of the corresponding monocationic species 1(.+) generated by chemical or electrochemical oxidation are reported. IR and Raman studies of 1 and the derived 1(x)PF(6) salt and ESR studies of 1(.+) are described. The results of this experimental investigation are compared with those of semiempirical calculations performed using the PM3 or AM1 modeling and simulation programs, and of a normal coordinate analysis. This comparison affords additional evidence for a symmetry breakdown in radical cations based on such Ms(TTF) systems. An asymmetrical spin density distribution in the 1(.+) radical cation is also confirmed by ESR measurements.