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

[Marcin Dulak]

Hi,

On 03/20/2015 04:50 PM, Eric Hermes wrote:
> Marcin,
>
> On 3/20/2015 6:56 AM, Marcin Dulak wrote:
>> Hi,
>>
>> On 03/19/2015 07:16 PM, Eric Hermes wrote:
>>> 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.
>> i would not use the non-semicore datasets (that's how we call setups 
>> now) like Pd 10-electron anymore.
>> Most modern pseudopotentials (http://www.physics.rutgers.edu/gbrv/ 
>> http://fpmd.ucdavis.edu/qso/potentials/index.htm 
>> http://www.abinit.org/downloads/PAW2/OLD-VERSIONS/JTH-TABLE-0.1/index.html)
>> dropped the idea of non-semicore ones because they are more difficult 
>> to create.
>> We don't have a working 10-electron Pd in generator2 (yet?). The 
>> parameters for non-semicore datasets in generator2.py are just so 
>> there is something there - they are not meant to be used.
>> On the other hand we have an "optimized" version of 18-electron Pd:
>> python -c "from gpaw.atom.generator2 import main as g; g(['Pd', '-f', 
>> 'PBE', '-sw', '-P', '4s,5s,4p,5p,4d,0.5d,F', '-r', '1.98,2.5,2.05', 
>> '-0', '5,1.69', '-pl', 'spdfg,-1.5:1.5:0.01'])"
>> Try starting from the above.
>
> Where do those parameters come from? I do not see them in 
> generator2.py. How trustworthy are the default parameters in 
> generator2.py? Where can I find the dataset parameters for the 
> elements that have been "optimized"?
this is still work in progress, but we are "optimizing" all elements.

Best regards,

Marcin
>
>> Best regards,
>>
>> Marcin
>>>
>>> Thank you,
>>> Eric Hermes
>>>
>>
>>
>