Using a dimer approach to examine the electron-molecular vibration coupling in BEDT-TTF based charge-transfer salts

A dimer approach has been utilized for the analysis of fundamental vibrations in spectra of the BEDT-TTF based monovalent charge-transfer salts. The calculation allowed us to reproduce positions of observed intense i.r. “vibronic” bands and to estimate strength of the intermolecular interaction in the compound. It shows also that the coupling in the (BEDT-TTF+)2 dimer may take effect not only on totally symmetric aB modes but also on vibrations of other symmetry species.