How random has been the historical expansion of the chemical space?

Information about the chemical space gathered in Reaxys database can be used to test whether the chemical space has being growing randomly or not during the last 221 years. To do so, we need to compare the data with a random model using some statistical measures in order to quantify the differences. In this talk, we will show (i) the main aspects of the Erdős–Rényi model we used to test the randomness of the chemical space growth, (ii) that the chemical space has been "moving away" from randomness at rate close to be an exponential rate and (iii) similar results for some chemical families like rare earths, organic and inorganic chemicals and others.