An accurate numerical consideration of one-dimensional (1D) spinless fermion model with next-nearest-neighbor interactions is carried out for the electron concentration ρ=4/7. It is shown that depending on the parameters of the model, it can be either Luttinger liquid or bipolaron liquid. In the former case, competing interactions can result in a smooth behavior of one-electron distribution function at the Fermi surface with a divergence in the second derivative with respect to the quasimomentum (and not in the first one, as usual). In this connection, uncommon photoemission spectra for some 1D conductors can be explained qualitatively.

• Received 24 August 2000

DOI:https://doi.org/10.1103/PhysRevB.64.033102