Collision Diagnostics Dataset for Over-squashing as Transport Congestion: A Sandpile Dynamics Perspective

This dataset contains the controlled synthetic dumbbell mechanism benchmark used for the Collision Diagnostics Dataset artifact associated with the paper "Over-squashing as Transport Congestion: A Sandpile Dynamics Perspective". It supports the collision diagnostics analysis, which tests the relationship between transport congestion and representation collision among label-discordant pairs. The release includes the PyTorch dataset, the derived plot CSV, the generated collision diagnostics figure, metadata summaries, checksums, and scripts for regenerating the plot data. This is a controlled synthetic mechanism benchmark, not natural empirical graph data.