Learning the nature of the charge-density wave distortion in TTF-TCNQ from resonant Raman scattering

The out-of-plane distortion of the TCNQ molecule in the charge-density-wave state of TTF-TCNQ is confirmed by the low temperature activation of the normally-infrared-active B3u modes of vibration of the TCNQ molecule in the resonant Raman-scattering spectrum.