This is a temporal higher-order network dataset, which here means a sequence of timestamped simplices where each simplex is a set of nodes. In email communication, messages can be sent to multiple recipients. In this dataset, nodes are email addresses at a European research institution. The original data source only contains (sender, receiver, timestamp) tuples, where timestamps are recorded at 1-second resolution. Simplices consist of a sender and all receivers such that the email between the two has the same timestamp. We restricted to simplices that consist of at most 25 nodes. Some basic statistics of this dataset are:

• number of nodes: 998
• number of timestamped simplices: 234,760
• number of unique simplices: 25,791
• number of edges in projected graph: 29,299

Data restricted to simplices with at most 25 nodes:

• email-Eu.tar.gz (timestamped simplices)
• email-Eu-proj-graph.tar.gz (weighted projected graph)

Full data without restriction on simplex size:

• email-Eu-full.tar.gz (timestamped simplices)
• email-Eu-full-proj-graph.tar.gz (weighted projected graph)

If you use this data, please cite the following papers:

• Simplicial closure and higher-order link prediction.
  Austin R. Benson, Rediet Abebe, Michael T. Schaub, Ali Jadbabaie, and Jon Kleinberg.
  Proceedings of the National Academy of Sciences (PNAS), 2018. [bibtex]
• Local Higher-order Graph Clustering.
  Hao Yin, Austin R. Benson, Jure Leskovec, and David F. Gleich.
  In Proceedings of KDD, 2017. [bibtex]
• Graph Evolution: Densification and Shrinking Diameters.
  Jure Leskovec, Jon Kleinberg, and Christos Faloutsos.
  ACM Transactions on Knowledge Discovery from Data, 2007. [bibtex]