Elastic and Piezoelectric Property Calculation with PAW Pseudopotential

Running Abinit Response calculations
1

Hi,

I am trying to find Elastic and Piezoelectric constants for my material. I used the input as mentioned in the tutorial here - elastic - abinit . But my calculation isn’t running as because I chose PAW pseudopotential (of type *.GGA_PBE-JTH.xml). Is there any workaround for this? I need to use PAW pseudopotential to be consistent with the other calculations.

Here’s the output error:
— !ERROR
src_file: m_chkinp.F90
src_line: 2570
mpi_rank: 0
message: |
You are performing a DFPT+PAW calculation using a GGA XC functional:
Response to strain perturbation is not yet available!
…
And the input file is in the attachment -
piezo4.abi (3.2 KB)

2

Dear sms,
The elastic constant is indeed not (yet) implemented for PAW-GGA…
The workaround is to do it from finite difference if you really need to use PAW, otherwise just switch to norm-conserving pseudopotentials (it will cost more ecut and, hence, CPU time but you’ll have access to DFPT capabilities).
Best wishes,
Eric

3

Another option is to do those specific calculations in LDA, imposing ixc 7 for example. It’s not fully consistent, but as your psi0 and so on are GGA, the main approximation is in the Vxc, which is often small.

4

Thanks!
It works this way with ixc 7