Redistribution of charge in the proximity of the spin-Peierls transition:: 13C NMR investigation of (TMTTF)2PF6

C-13 nuclear magnetic resonance (NMR) investigations were carried out for a one-dimensional organic conductor, (TMTTF)(2)PF6, to determine the charge dynamics and configuration in the proximity of the spin-Peierls phase-transition temperature, T-sP. Although no obvious NMR line splitting associated with the charge-ordering transitions in the intermediate paramagnetic states was observed, the charge separation amplitude was estimated to be rho co similar to 0.14 using the C-13 NMR spin-lattice relaxation rates for the distinct lines. The abrupt decrease in the NMR linewidth below 25 K and the small anisotropy of the NMR linewidth in the spin-Peierls phase indicate the possible redistribution of the charge separation in the proximity of T-sP. The low-temperature electronic states of (TMTTF)(2)PF6 are discussed from a microscopic point of view.