Maximum absolute errors in $c_i$

Iterations (I)

cFEM

TH

Exact PNP

20

0.0700

0.0028

8.62e−2

40

0.0032

0.00125

5.4e−3

60

0.00253

0.00064

3.3691e−4

100

0.00194

0.00114

4.2114e−5

140

0.0014

0.00106

5.2643e−6