You may be interested in seeing this comparison of electrostatic potential maps generated by ChimeraX, iCn3D, and PyMOL:

https://proteopedia.org/wiki/index.php/Electrostatic_potential_maps 

and the related topic

https://proteopedia.org/wiki/index.php/Missing_residues_and_incomplete_sidechains
which suggests using AlphaFold models for electrostatic potential maps when the empirical model lacks sidechains of charged amino acids on its surface (very common).

-Eric Martz
http://martz.molviz.org