Electron-electron interaction strength in tetrathiafulvalenium-tetracyanoquinodimethanide (TTF-TCNQ)

Abstract
The experimental information on the relative strength of the repulsive electron-electron interaction in tetrathiafulvalenium-tetracyanoquinodimethanide (TTF-TCNQ) is summarized. From inelastic-electron-scattering data and analysis of the nuclear-spin-lattice relaxation measurements, we conclude that the effective Coulomb interaction is not dominant, and that the relative strengths on the TTF and TCNQ chains are similar.