Characterization of the unoccupied and partially occupied states of TTF-TCNQ by XANES and first-principles calculations

J. Fraxedas, Y.-J. Lee, I. Jimenez, R. Gago, R.M. Nieminen, P. Ordejon, E. Canadell

Research output: Contribution to journalArticleScientificpeer-review

47 Citations (Scopus)
107 Downloads (Pure)

Abstract

We report a combined experimental and theoretical study of the unoccupied electronic states of the neutral molecular organic materials TTF (tetrathiafulvalene) and TCNQ (7,7,8,8-tetracyano-p-quinodimethane) and of the one-dimensional metallic charge transfer salt TTF-TCNQ. The experimental density of states (DOS) is obtained by x-ray absorption near edge spectroscopy (XANES) with synchrotron light and the predicted DOS by means of first-principles density functional theory calculations. Most of the experimentally derived element-specific XANES features can be associated to molecular orbitals of defined symmetry. Because of the planar geometry of the TTF and TCNQ molecules and the polarization of the synchrotron light, the energy dependent σ or π character of the orbitals can be inferred from angular dependent XANES measurements. The present work represents the state of the art analysis of the XANES spectra of this type of materials and points out the need for additional work in order to elucidate the governing selection rules in the excitation process.
Original languageEnglish
Article number195115
Pages (from-to)1-11
JournalPhysical Review B
Volume68
Issue number19
DOIs
Publication statusPublished - 2003
MoE publication typeA1 Journal article-refereed

Keywords

  • DFT
  • organic conductors
  • XANES

Fingerprint

Dive into the research topics of 'Characterization of the unoccupied and partially occupied states of TTF-TCNQ by XANES and first-principles calculations'. Together they form a unique fingerprint.

Cite this