The B3LYP/DZP++ adiabatic electron affinity (AEA) of nine (non)-alternant polycyclic aromatic hydrocarbons are reported and discussed. Calculations became feasible for molecules this size by projecting out the near-linearly dependent part of the one-electron basis. Non-alternant PAH consisting of an alternant PAH core modified by peri-annulation with unsaturated five-membered rings (CP-PAHs) possess markedly enhanced AEAs. (c) 2008 Elsevier B. V. All rights reserved.