This example dataset corresponds to the paper https://arxiv.org/abs/1907.01898. Moscovich, A., Halevi, A., Andén, J., & Singer, A. (2020). Cryo-EM reconstruction of continuous heterogeneity by Laplacian spectral volumes. Inverse Problems, 36(2), 024003. Expresses the ChannelSpin feature without ChannelStretch. Includes 54 generated volumes sized (54,54,54) and stack of 10000 projection images (54,54). The dataset was originally created by the paper authors in using several legacy MATLAB functions denoted by "gen_fakekv*". That dataset was converted into a compressed Numpy (.npz) dataset compatible with ASPIRE-Python. The dataset includes parameters (rotations, amplitudes, states, etc) required to simulate an equivalent image stack in Python starting from the volumes, or used directly to provide a ground truth reference. Alternatively, these parameters can be modified to generate different image stacks.