Identification of dimerization phase transitions driven by Peierls and other mechanisms

One-dimensional (1D) electronic structure is characteristic of face-to-face stacks of planar π-electron donors and/or acceptors. Dimerization phase transitions at Tc < 400 K occur for various stacking motifs. Excitations of the dimerized phase are used to distinguish between dimerization driven by electron-phonon coupling (Peierls) and other mechanisms in correlated systems with spin and charge degrees of freedom.