3-projector PAW construction for GW

qnclqq · Post by **qnclqq** » Wed Mar 29, 2017 5:40 pm

When learing Abinit through the tutorial of "PAW3", I find a paragraph includes the following words,

"If you need to perform calculations which involve the Fock operator or unoccupied states - like in GW calculations for instance - you will probably need at least three projectors. You might also want to add extra projectors in completely unoccupied l-channels"

Could anyone told me more details about why 3-projector is essential. Whether the result reliable if I calculate GW correction with a 2-projector PAW?

Since I have tried to construct 3-projecotr by AtomPAW for Ti, but failed because I couldn't find a group of energy for all the projectors that cause no ghost states meanwhile. How to constucture a well performed PAW?

Another problem is how can I interpolate GW calculation for full band structure? I searched the fourm and find the script "ab_extended_scissors_guess.py" may works, but I don't have *.nc or .GW after the calculation finished. (Abinit version 8.0)