Hi ATK support:
I tried to plot the Hartree difference potential to check the central region is enough long or not,
the plot is in the attachment.
but I do not know it is flat or not?, because I set the Y axis is from -1 to 1 eV. when I set Y -0.06 to 0.12 eV , it seems not flat.
so my question is how to set Y axis region when I check the length of central region.