ABINIT Discussion Forums

Hello,

I'm having some trouble understanding the units Anaddb writes out the piezoelectric tensor with.
The piezoelectric tensor should have units of m/V (usually on the order of pm/V), but Anaddb claims the units it's using are C/m^2, which isn't equivalent to m/V.
I'm further confused by this recent thread https://forum.abinit.org/viewtopic.php?f=10&t=3822 in which the ABINIT user has output of pC/N, which is equivalent to m/V!

Can anyone shed some light on this?
Thanks,
-Ali

Dear Ali,
You have several definitions of the piezoelectric tensor (e, d, etc ) with different units and you can select which one you want through the anaddb flag piezoflag (https://docs.abinit.org/variables/anaddb/#piezoflag).
You can also find some details in the former Phys. Rev. B 72, 035105 (2005) paper of Don Hamann who implemented this response in Abinit (https://journals.aps.org/prb/abstract/10.1103/PhysRevB.72.035105).
Best wishes,
Eric

ebousquet wrote:Dear Ali,
You have several definitions of the piezoelectric tensor (e, d, etc ) with different units and you can select which one you want through the anaddb flag piezoflag (https://docs.abinit.org/variables/anaddb/#piezoflag).
You can also find some details in the former Phys. Rev. B 72, 035105 (2005) paper of Don Hamann who implemented this response in Abinit (https://journals.aps.org/prb/abstract/10.1103/PhysRevB.72.035105).
Best wishes,
Eric

Thank you for those references, they helped clear things up a lot!