I was looking at the RAK "Using Liberate to Characterize Standard Cells". I was able to run it and see the .lib file being created from the SPICE netlists and the model. The main script pulls in a user data file "userdata/userdata.lib". This contains the area of each cell.
My question is: if I have to design my own library from a PDK, how does one get the area of these cells and into the correct format? It would help to see the link between Virtuoso or some other tool, and Liberate.