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Hello,

I have got the PARCHG file using all the required key words in the INCAR.
I know that PARCHG file has the local band decomposed charge density info below (for -ve EINT) and above (for +ve EINT) the fermi level.

I was able to plot the STM images using P4VASP both at constant current and constant height. I see different images at constant current and constant height plots.

I know what they mean in an STM experiment.

But in P4VASP can someone explain the technical/scientific details of how/why the STM images change with constant current and height since we are using the same PARCHG file for plotting both.

Thank you in advance

Constant height and constant current images should be qualitatively similar. That is, the location of the bright spots should be nearly the same. The images may look different because the tunneling current decreases exponentially with height, so a constant height image tend to show only the brightest spots.