You can produce cube file of electrostatic potential, and then load it into VMD and show gradient lines (use drawing method of "fieldlines"), which portrays electric field.

Best,

Tian

You can use ORCA to conduct calculation under electric field and generate .molden file used for wavefunction analysis in Multiwfn.

For example, to add external electric field vector of (0,0,-0.01) a.u., you should add the following content to input file.

%scf
  efield 0.0, 0.0, -0.01 
end

Best,

Tian

I read in the Mutiwfn manual that it can calculate ESP and the corresponding electric field. So I am wondering if is it possible to calculate similar electric fields by ORCA calculations and visualize them via an external package like VMD ..?

Could you please give me some details..? Thanks.

Best,
Sayan