Open Database of Phase Diagrams? Is there some kind of database that has information about phase diagrams of different substances? I'm mostly looking for phase diagrams of elements (silicon, iron, hydrogen, etc.) because I'm trying to write a planetary generator, but I cannot find any information about the mathematics of a phase diagram.

Better yet, is there some way to simply approximate the phase diagrams of different compounds? I'm looking for simulation complexity and variation more than I want realism.
I believe you can compare many of the models with a search engine.
http://www1.asminternational.org/asmenterprise/apd/AdvancedSearchAPD.aspx