Universal jellium BCS picture for Peierls and spin-Peierls phase transitions

Both metal-insulator Peierls and antiferromagnetic spin-Peierls dimerized phase transitions are observed to have a BCS electron-phonon interaction parameter which is compatible with the jellium value λ = 2/3π ≈ 0.21

Dynamical and symmetry effects in the Kπ ratio in the central plateau

Produced-mass and internal-mass effects are used along with symmetry considerations in a general peripheral structure to account for the Kπ ratio in the central plateau with no free parameters. The increase of the ratio with increasing q is accounted for. © 1974 The American Physical Society