Are all the stable phases in the Materials project lattice dynamically stable?


#1

I find that, for some materials, there are many stable phases available in the Materials Project. Are these phases all lattice dynamically stable, namely, if we calculate their phonons, there will be no imaginary modes?

Thanks.


#2

So there are several layers to this answer:

We don’t have phonon calculations for all our of compounds, so dynamical stability is not guaranteed.

We do have about 1,500 phonon bandstructures, which can be assessed for dynamic stability.

We also have almost 14K elastic tensors, that can also be assessed for dynamic stability.


#3

Many thanks.

The material I was talking about is Li2MnSiO4, where there are more than a dozen of phases given in the Materials project. However, there are no phonons available for these phases. Does this mean that the lattice-dynamic stability of these phases are not guaranteed?


#4

That is correct. The phonon calculations are very slow and we’re working on a recommendation system where you could vote up the priority of phonon calculations for that material, but its still in the works.