Especially in complex cases with many domains and GGI interfaces the convergence of scalar equations (i.e. E-Pot for electric potential) can become slow, resulting in a large number of iterations to obtain a steady state result of the scalar. The following Expert Parameters will ensure a tighter convergence in the linear solver and thus result in reduced iterations for steady state results of scalar. Either use solver target reduction scalar = 0.0005 or mg small grid = 50 solver target reduction scalar = 0.01