Metallic bands in chevron-type polyacenes.

We present electronic structure calculations based on a single-parameter plane wave expansion method for basic graphene building blocks, namely -oligophenylenes and -oligoacenes, revealing excellent agreement with density-functional theory. When oligophenylene molecules are joined through (zigzag) or (chevron) junctions, the resulting molecular dimers and polymers exhibit a semiconducting character. While zigzag dimers of oligoacenes also exhibit gapped electronic structures, their chevron-phase features a sharp metallic band at the Fermi energy.