We have used LJ reduced units throughout this work, with energies, lengths, temperatures, pressures, and times given in units of ε, σ , ε/k B , ε/σ 3 , and τ ≡ m 0 σ 2 /ε, where m 0 is the unit of mass and k B is the Boltzmann constant. We note that setting ε = 1.8 kcal/mol and σ = 3.2 Å gives behaviour consistent with the experimental behaviour of perylene, i.e. a density of 1.1 g/cm 3 at 560 K and 1 atm for a system with κ and κ approximately those of perylene in Table , and so the parameter range studied should be representative of the behaviour of a variety of OSCs given this choice of ε and σ .