The effect of the first-order phase transition occurring around 220 K on the crystal and electronic structure of the molecular superconductor (BEDO-TTF)2ReO4 · H2O has been studied. The crystal structure at 170 K has been determined and it is found that the main structural change resulting from the phase transition is connected with a rotation of the ReO-4 anions. This rotation leads to changes in the S⋯S and S⋯O intermolecular contacts within the BEDO-TTF donor layers. How these structural changes affect the electronic structure of the salt is studied by comparing the transfer integrals for the different donor⋯donor intermolecular interactions calculated for the room temperature and 170 K crystal structures. It is shown that Fermi surfaces for the 170 K and room temperature structures are very similar, do not exhibit nesting properties, and can be described as resulting from the hybridization of superposing ellipses.
- 61.66.Hq Organic compounds
- 74.70.Kn Organic superconductors
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics