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Mirror Chern number and PAW pseudopotentials

Open mbosnar opened this issue 3 years ago • 2 comments

Dear z2pack developers, I am trying to calculate the mirror Chern number using the z2pack. I am using QuantumESPRESSO 5.3 and pw2z2pack.x program from here: https://github.com/Z2PackDev/Z2Pack/tree/master/2.1.x/examples/fp/pw2z2pack.

The calculation crashes on the step involving pw2z2pack.x with the following error:

 Error in routine pw2z2pack (1):
 lsym =/=0 not implemented with USP

This seems to be caused by the pseudopotential choice (note however that I am using PAW, not ultrasoft). The problem can be reproduced in the SnTe example, where if norm-conserving pseudopotentials are replaced by PAW, the calculation terminates with this error.

Is there a way around this error, aside from the use of norm-conserving pseudopotentials?

Regards, Mihovil Bosnar

mbosnar avatar Mar 15 '22 13:03 mbosnar

Is there a way around this error

Not that I'm aware of, unfortunately. This is probably not a fundamental limitation, just that no one has taken the time to implement it in pw2z2pack.

note however that I am using PAW, not ultrasoft

If I'm not mistaken, the "ultrasoft" classifier in Quantum ESPRESSO's terminology includes both PAW and Vanderbilt PP. See e.g. the is_ultrasoft="true" statement in this PAW potential.

greschd avatar Mar 16 '22 16:03 greschd

Is there a way around this error

Not that I'm aware of, unfortunately. This is probably not a fundamental limitation, just that no one has taken the time to implement it in pw2z2pack.

Ok, thank you.

note however that I am using PAW, not ultrasoft

If I'm not mistaken, the "ultrasoft" classifier in Quantum ESPRESSO's terminology includes both PAW and Vanderbilt PP. See e.g. the is_ultrasoft="true" statement in this PAW potential.

I didn't know that, thank you. Indeed, all PAW setups that I use have this statement.

mbosnar avatar Mar 16 '22 16:03 mbosnar