**M. Ménard and C. Bourbonnais \***

Regroupement Québécois sur les Matériaux de Pointe, Départememt de physique, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; menarmar@gmail.com

**\*** Correspondence: Claude.Bourbonnais@Usherbrooke.ca

Received: 17 September 2020; Accepted: 6 October 2020; Published: 16 October 2020

**Abstract:** The one-dimensional extended Hubbard model with lattice dimerization and alternated site potentials is analyzed using the renormalization group method. The coupling of electrons to structural degrees of freedom such as the anion lattice and acoustic phonons is investigated to obtain the possible instabilities against the formation of lattice superstructures. Applications of the theory to anionic and spin-Peierls instabilities in the Fabre and Bechgaard salts series of organic conductors and ordered alloys are presented and discussed.

**Keywords:** interacting electrons in one dimension; electronic and lattice instabilities; renormalization group method; organic conductors
