Conformations and torsional potentials of poly(3-hexylthiophene) oligomers: Density functional calculations up to the dodecamer

► Fully relaxed non-planar conformations of P3HT oligomers investigated. ► The lowest energy oligomers have ≈74° hexyl chain and ≈47° backbone twist angles. ► Non-planar oligomers have ≈0.03 eV per monomer less energy than planar oligomers. ► Convergence of backbone and hexyl torsional potentials achieved by octamer.