The alpha '' phase of syndiotactic polystyrene (alpha '' sPS) is a frustrated "superstructure" that houses three triplets (three clusters of three chains, thus nine chains) in a trigonal unit-cell. The hko electron diffraction pattern of alpha '' sPS single crystals displays, in addition to sharp spots, a number of diffuse spots located at 1/3 and 2/3 between the sharp spots. The diffuse spots correspond to the intersection of streaks. They are due to a structural disorder linked with the fact that the "frustrated" triplet in the cell has three-fold-symmetry but is housed in a hexagonally symmetric environment. Two equivalent crystallographic positions of this triplet, corresponding to 0 degrees and 180 degrees (or 60 degrees) azimuthal settings are thus possible. Modeling of the diffraction features associated with this disorder reproduces to a significant detail the experimentally observed pattern. The frustrated character of the sPS alpha '' phase structure thus accounts for both the very detailed sharp reflections and for the diffuse components of the diffraction pattern. (C) 2014 Elsevier Ltd. All rights reserved.