Geometry optimization using HSE06 DDH

[abhinav]

Why am I unable to use HSE06MetallicLocalDDH, HSE06LocalDDH, or HSE06DDH for the "OptimizeGeometry " module? It shows that OptimizeGeometry requires forces/stress, but the calculator does not allow them. Is there any other way to do that? FYI, I'm working on MXene.

[Anders Blom]

I believe with DDH you lose the connection between the forces and energy (i.e. zero forces are not necessarily the minimum energy), hence it's formally not available. But the discrepancies should be tiny, so just optimize the geometry with "normal" HSE and then add these more advanced options for the final computation of the electronic structure. That is, even if you could do optimization with DDH, the resulting geometry would not be significantly different.