“…Inorganic compounds, as CuGeO 3 3 or N aV 2 O 5 4 , show clear evidence in favor of the existence of spin-Peierls states with broken lattice symmetry. Even more complex phase diagrams are displayed by quasi 1D organic materials: the DI−DCN QI compounds 5,6 , the Bechgaard salts series (T M T SF ) 2 X and its sulfur analog (Fabre salts series) (T M T T F ) 2 X, where X denotes different monovalent anions (X = P F 6 , AsF 6 , ClO 4 , ...). These systems, which consist of stacks of weakly coupled chains, exhibit, at low temperature, several broken symmetry phases like charge-density-wave (CDW), spin-density-wave (SDW) and spin-Peierls (SP) before becoming superconducting 6,7 .…”