Abstract
We investigate the properties of a one-dimensional (ID) half-filled-band electron gas with both electron-electron and electron-phonon interactions. We estimate the variation of ID 2Kf dimerization pseudo-gap Δ as a function of umklapp scattering strength g3H or the correlation gap ΔH. The effect of pressure on the phase diagram is analyzed in connection with the available data on (TMTTF)2X (X=PF6 AsF6 Br.…) compounds.