Structural and electronic properties of $\alpha ,\beta$-(BEDT-TTF)${}_2$I${}_3$ and $\kappa$-(BEDT-TTF)${}_2$X${}_3$ (X=I,F,Br,Cl) organic charge transfer salts

Abstract

(BEDT-TFF)${}_2$I${}_3$ charge transfer salts are reported to show superconductivity and pressure induced quasi two-dimensional Dirac cones at the Fermi level. By performing state of the art ab initio calculations in the framework of density functional theory, we investigate the structural and electronic properties of the three structural phases $\alpha$, $\beta$ and $\kappa$. \edit{We furthermore report about the irreducible representations of the corresponding electronic band structures, symmetry of their crystal structure, and discuss the origin of band crossings. Additionally, we discuss the chemically induced strain in $\kappa$-(BEDT-TTF)${}_2$I${}_3$ achieved by replacing the Iodine layer with other Halogens: Fluorine, Bromine and Chlorine. In the case of $\kappa$-(BEDT-TTF)${}_2$F${}_3$, we identify topologically protected crossings within the band structure. These crossings are forced to occur due to the non-symmorphic nature of the crystal.} The calculated electronic structures presented here are added to the organic materials database (OMDB).

7 pages, 4 figures, 2 tables

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• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• A Higher-Accuracy van der Waals Density Functional
• Topological quantum chemistry
• Dirac materials
• Charge Ordering in alpha-(BEDT-TTF)2I3 by synchrotron x-ray diffraction
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Cited by in corpus (3)

• Tilt-induced kink in the plasmon dispersion of two-dimensional Dirac electrons
• Chemical-Strain Induced Tilted Dirac Nodes in (BEDT-TTF)${}_2$X${}_3$ (X = I, Cl, Br, F) Based Charge-Transfer Salts
• Symmetry analysis of odd- and even-frequency superconducting gap symmetries for time-reversal symmetric interactions