[gpaw-users] Generating a core-hole setup with generator2

[Eric Hermes]

Hello,

I am attempting to generate a setup for Pd with a core hole in the 3d 
state using generator2. If I generate the setup with '-f PBE -w -s Pd 
--core-hole 3d,1.0', several new additional bound states appear that did 
not exist in the ground-state calculation (2 s-states, 2 p-states, and 3 
d-states). Here is an example output from this calculation:
https://gist.github.com/ehermes/6c85184e16d43acb6992

If I instead generate the setup by specifying the electron configuration 
with '-C' (as [Ar] 3s2 3p6 3d9 4s2 4p6 4d10 5s1), I receive no error and 
get what appears to be a working core-hole setup for Pd. In addition, 
the total all-electron scalar-relativistic energy difference between the 
ground state and core-hole Pd atom is quite close to the experimental 
metallic Pd 3d binding energy (334.2 eV vs ~335.2 eV). This indicates to 
me that this procedure works. However, I am not using the "--core-hole" 
argument to do this. Is what I am doing valid? Here's the output file 
from the calculation I have described:
https://gist.github.com/ehermes/3aec73bb427bbc6efe7c

Also, I understand that the setups used for the ground state Pd and 
core-excited Pd should be of comparable quality, and that the best way 
to ensure this is to generate both setups as similarly as possible. 
However, the default setup parameters for Pd in generator2 do not seem 
to produce a good quality setup. While the official setups produce 
lattice constants (3.946 for 10-electron and 3.937 for 18-electron) that 
are in fairly good agreement with an all-electron FP-LAPW calculation 
(3.948 angstrom), the default Pd setup generated by generator2 predicts 
a lattice constant that is more than 0.02 angstrom too large (3.972). If 
I use the cutoffs from the official 10-electron setup ([2.3, 2.5, 2.2]) 
instead of generator2's default cutoff (2.4), the lattice constant is in 
much better agreement (3.958). As I am not an expert in generating 
pseudopotentials, I wonder what the best procedure here is, and how to 
best measure the quality of a setup. Any advice would be appreciated.

Thank you,
Eric Hermes

-- 
Eric Hermes
J.R. Schmidt Group
Chemistry Department
University of Wisconsin - Madison