M. Meneghetti, Dynamic modulation of electron correlation by intramolecular modes in charge-transfer compounds, PHYS REV B, 60(23), 1999, pp. 15472-15475
Electron-phonon and electron-electron interactions are in competition in de
termining the properties of molecular charge-transfer conductors and superc
onductors. The direct influence of phonons on the electron-electron interac
tion was not before considered and in the present paper the coupling of int
ramolecular modes to electron-electron interaction (U-vib interaction) is i
nvestigated. The effect of this coupling on the frequency of the normal mod
es of a dimer model is obtained and it is shown that frequency shifts of th
e Raman active modes are directly related to this coupling. The results are
used to obtain the values of the U-vib coupling constants of intramolecula
r modes of a representative molecule of charge-transfer conductors, like te
tramethyl-tetratiafulvalene. Consequences of this coupling on the electron
pairing are also suggested. [S0163-1829(99)01444-7].