Ab initioelectronic structure of solid coronene: Differences from and commonalities to picene

Abstract

We have obtained the first-principles electronic structure of solid coronene, which has been recently discovered to exhibit superconductivity with potassium doping. Since coronene, along with picene, the first aromatic superconductor, now provide a class of superconductors as solids of aromatic compounds, here we compare the two cases in examining the electronic structures. In the undoped coronene crystal, where the molecules are arranged in a herringbone structure with two molecules in a unit cell, the conduction band above an insulating gap is found to comprise four bands, which basically originate from the lowest two unoccupied molecular orbitals (doubly-degenerate, reflecting the high symmetry of the molecular shape) in an isolated molecule but the bands are entangled as in solid picene. The Fermi surface for a candidate of the structure of Kxcoronene with x = 3, for which superconductivity is found, comprises multiple sheets, as in doped picene but exhibiting a larger anisotropy with different topology.

Accessing Surface Brillouin Zone and Band Structure of Picene Single Crystals

“…The first-principles band structure of single crystalline picene, first obtained in [18] and shown here for three different implementations [18][19][20] of the exchange functional etc, is also displayed in Fig. 3(b).…”

“…[18,19] for theoretical method), Perdew-Burker-Ernzerhof (PBE) and B3LYP [20]. The calculated DOS was shifted in binding energy to match the experimental HOMO-1 derived peak.…”

Role of potassium orbitals in the metallic behavior ofK3picene

“…A large K 3+ 3 (K 3 picene) 12 cluster taken from our crystalline structure (Ref. [10]) has been solved using the B3LYP functional and a PC1 Gaussian basis [29].…”

“…Parallel to the experimental work there have been several theoretical calculations of the electronic structure of potassium-intercalated picene [8][9][10][11][12][13][14][15]. According to x-raydiffraction experiments, potassium enters into the intralayer herringbone arrangement of picene molecules.…”

Structural and electronic changes of pentacene induced by potassium doping

“…Potassium enters within the PAH herringbone structure (intralayer doping) where there is space enough for three dopant atoms. This was the consensus immediately after the discovery of superconducting properties of K-doped picene [1, [4][5][6][7][8][9].…”