Resolving discrepancy in stable structures between phase diagram and materials explorer apps

Dear treasured colleagues,

In the Phase Diagram app, if I search the Si-O system, the SiO2 structure that is along the GGA/GGA+U convex hull is mp-546794 (with formation energy -3.035 eV/atom). However, the SiO2 structure that has the lowest energy above hull in the Materials Explorer is mp-7000. This kind of difference occurs for several materials (e.g. O2 in the same Si-O system).

What is the underlying reason for this difference? I am assuming that the energy above hull presented in both the Materials Explorer and Phase Diagram apps both are using oxide corrections. Is it some subtlety with the r2SCAN mixing scheme even though I am not looking at the mixed phase diagram?

Hi @Andrew_Rosen
Thanks for the feedback. mp-7000 is an r2SCAN entry, so it does not appear on the GGA/GGA+U hull in the phase diagram.
If you choose the r2SCAN or GGA/R2SCAN mixed hull in the phase diagram, you will see mp-7000 appear as the lowest compound.
Hope this helps!

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