Dear Muhammad,

the electrostatic potential in WIEN2k is calculated from the total potential, which consists of the Hartree potential from the electron density and the nuclear potential from the atomic cores.

By default it outputs the total potential, which is typically shifted such that the average interstitial potential is zero bbut of course this depends on your settings.

> First run lapw0 correctly. The electrostatic potential is computed using the lapw0 program with -pot option. Ensure you ran following

bash

lapw0 -pot

This will generate the file case.vcoul.

>> Use x lapw0 for proper averaging:

If you need the muffin-tin and interstitial potentials properly averaged, then

also run:

bash

x lapw0

and check the output for potential shifts.

>>> Large negative values may indicate an arbitrary potential shift.

The programm sometimes defines potentials relative to an arbitrary reference.

You may need to align your potential to a known reference for instance the

vacuum level or Fermi level.

Check case.scf/case.energy to see if your potential is being shifted relative to

E_Fermi. You may need to subtract E_Fermi to get physically meaningful values.

>>>> Next Post-Processing with lapw5... to extract the 3D electrostatic potential in a usable format:

bash

lapw5 -c -p , which generates scalar potential in 3D

You can then use xcrysden or VESTA to visualize it. If the values are still unreasonable, try subtracting the average interstitial potential which can be found in case.output0. Alternative, you coulddof course use optic for potential analysis. If you need the potential for further analysis as for instance band alignment, consider using the optic module:

bash

lapw0 -opt !!!it prepares potential for optic calculations

optic !!!and then processes potential data

Expected Range of Values should be on the order of a few eV.

Recommend more: rerun SCF with stricter criteria&& double-doble check your .in0 files...

Hope, it helps ;)

Thank you for your detailed answer. However, I am still facing the same issue. My minimum value is approximately -2 × 10⁵, while my maximum value is around 1.19. I calculated the electrostatic potential using both vtotal​ and a separate calculation using only vcoul​, but I’m still getting extreme values. Is this normal? If not, how can I resolve this issue?