GW + response calculations

[aliwho]

Hello,

Is it possible to use GW in response calculations? I'm specifically interested in non-linear optical (NLO) properties.

From the NLO tutorial, the steps involved in calculating the NLO properties are (1) self-consistent calculation in the IBZ; (2) non self-consistent calculations to get the wave-functions over the full BZ; (3) ddk calculation, (4) derivatives with respect to electric field and atomic displacements, and (5) the NLO step.

I have 2 main questions:
1) From the first GW tutorial, I understand that it is possible to do a self-consistent calculations using GW. Can I take the output (wave function and density) of a self-consistent GW calcuation and use it as the input for step (1) in a NLO calculation? If I'm understanding things correctly, the subsequent steps should remain the same. Is this correct?

2) Another concern I have is that the GW tutorial discussion on self-consistent calculations states that "the code calculates the quasiparticle energies and wavefunctions and outputs them in a QPS file," as well as writing the original KS wave function. Even if the answer to my first question is positive, It's not clear to me that this output can be used as an input to step (1) of the a NLO calculation. Is it possible to do this?

Best,
-Ali

PS -- I wasn't sure if this post made more sense in the GW board or the Respose Calculation board. I placed the here because my end goal is a response calculation, but please move it if this is not the best place to ask.