First-principles study of the structures and vibrational frequencies for tetrathiafulvalene TTF and TTF-d(4) in different oxidation states

The structures and vibrational spectra of tetrathiafulvalene (TTF), TTF-d(4 ), and their radical cations have been extensively studied using the projec tor augmented wave method, which allows first-principles molecular dynamics based on the density functional theory. The dependence of the bond lengths and vibrational frequencies on the molecular ionicity is discussed, and th e ionization energy, Coulomb repulsion, and spin-splitting parameter are al so derived.