One of the more powerful tools in materials screening is the computational phase stability diagram. Unfortunately, it is only utilized by a few research groups, and I thought that a comic book about them might improve the situation.
The project is taking a bit longer than expected…so I am releasing the comic page-by-page, with the first page below. This page is just an introduction; there will be about 5 more pages that fill in more details, with one post per page. The final post will provide the full comic as a PDF and will include an article with more details.
So without further ado – page 1!
To be continued…
2 thoughts on “Phase Diagram comic: part 1”
Nice comic! I have the same impression that phase diagram is underappreciated in the materials community because of its equilibrium nature. But equilibrium phase diagrams define the direction of any kinetic processes thus this information is very useful.
One question: should temperature be another important variable besides composition?
Temperature dependence can also be important but difficult to assess via first principles methods. We hope to get there at some point with Materials Project. In the meantime, we can still get decent estimates of stability by (i) assuming that only gases contribute to temperature dependence, since those have the greatest entropy and (ii) treating compounds with a small amount of metastability as essentially “stable” (e.g., 50 meV/atom or less) because those might be stabilized by temperature. However, temperature can only go so far and it is unlikely that a virtual compound that exhibits a decomposition energy of 200 meV/atom will be stable at any reasonable temperature. So even the 0K results can usually give you a good indicator of whether virtual materials are viable candidates.