The Gephi software package was used to visualize the generated reaction networks. In Gephi plots, node size can be made proportional to any graph property for emphasis, for example the in-degree or out-degree of the nodes. Plot layouts were rendered using Gephi's ForceAtlas2 function by setting the gravity parameter to 0.05 and scaling parameter to 4.0, and running this for 10 minutes without avoiding overlapping and then 20 minutes avoiding overlapping .