Generating Pseudopotentials
  1. At times custom pseudopotentials with more core electrons (such as tellurium 4d-orbitals) may be required. They can be made using the fhi98PP code, which is installed on wsx:/packages/fhi98PP/bin/Tools/psgen Please note that there is an online tutorial document. Initial .ini files can be found at the bottom of this page. Note that if you generate pseudopotentials directly from the provided .ini files, your produced pseudopotentials will not match up with those given on the same page, as they include a slight core correction. Let's discuss editing the .ini file. Here is a sample:

52.00 9 2 6 0.00 : z nc nv
1 0 2.00 : n l f
2 0 2.00
2 1 6.00
3 0 2.00
3 1 6.00
3 2 10.00
4 0 2.00
4 1 6.00
4 2 10.00
5 0 2.00
5 1 4.00
3 "t"
2 0.0 20.00 "t"
0 3.496 0 "t"
1 0.0 0 "t"
3 0.0 0.01 "t"

This is the .ini file for tellurium. The first three numbers on the first line are Z, number of core orbitals, and number of valence orbitals. Below that you see the orbitals, listed by quantum numbers and occupancy. Below that are specifications about the pseudopotential that we do not change. Note that core orbitals + valence orbitals = total orbitals. The orbitals accurately represented by the pseudopotential will be those labeled valence, which will be the last N orbitals, where N = number of valence orbitals. Therefore in order to make our enlarged te psp we simply change 9 and 2 to 8 and 3.

After editing your .ini file, to run the code:
# tcsh
# setenv FHIPP_PATH /packages
# tcsh /packages/fhi98PP/bin/Tools/psgen -xc 6 -g 23-V.GGA.ini
# A file named ncpp.cpi will be produced along with a bunch of fort.XX files. The important ones for our purpose are .40, .41, .42, and .43. All are referenced in ncpp.cpi and their contents must be pasted into it to complete it. A script should probably be written for this if it is to be done with any frequency.
# Finally, a header must be added to the psp. Examine that of another psp and make the necessary changes.

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