Hi
I am new to Comsol. I have tried to build a simple model resembling human head including three layers of skull, csf and brain using the provided conductivities. I then built a tri-pole electrode which the center one is grounded and the middle and the outer layer are given a current or current density.
My problem is that I fail to get any solution and I face an the following error:
Failed to find a solution.
Segregated group 1
Singular matrix.
There are 12414 void equations (empty rows in matrix) for the variable mod1.V
at coordinates: (-0.00104638,-0.000753554,0.10675), (-0.000753557,-0.00104637,0.10675), (-0.00119282,-0.000400008,0.10675), (0.0013,4.30826e-019,0.10675), (-2.29715e-020,0.00115,0.106625), ...
and similarly for the degrees of freedom (empty columns in matrix)
Returned solution is not converged.