Weak electron correlations and charge-density waves in TTF[M(dmit)2]2, with M = Ni, Pd

Static magnetic susceptibility measurements, performed at ambient pressure on single crystals of the quasi-1D conductors TTF[M(dmit)2]2 where M= Ni, Pd, link up to correlate the molar spin susceptibility χs of these charge-transfer salts with successive condensations of the carriers into static charge-density waves (CDW) and with the partial densities of states (DOS) at the Fermi level derived from tight-binding band-structure calculations. In both compounds, the highest temperature CDW instability is driven by the LUMO bands of the acceptor stacks. Comparison between the room temperature χs value and the calculated Pauli spin susceptibility shows that both compounds may be characterized by weak intramolecular repulsions U compared to the bandwidth W.