  We investigate the role of intra-molecular conformational disorder and
inter-molecular electronic interactions on the electronic structure of disorder
clusters of poly-p-phenylene vinylene (PPV) oligomers. Classical molecular
dynamics is used to determine probable molecular geometries, and
first-principle density functional theory (DFT) calculations are used to
determine electronic structure. Intra-molecular and inter-molecular effects are
disentangled by contrasting results for densely packed oligomer clusters with
those for ensembles of isolated oligomers with the same intra-molecular
geometries. We find that electron trap states are induced primarily by
intra-molecular configuration disorder, while the hole trap states are
generated primarily from inter-molecular electronic interactions.
