The solution in 3-dimensions was found for various multiples of the
potential function and the following graphs
are 2-d slices with the x-value set to 0, that is, in the middle
of the slab in the x-direction.
The multiple increased logarithmically as 10^n. Here are the plots
for various values of n and of resolution level.
n=0 low res, high res
n=1 low res
n=2 low res
n=3 low res, high res
n=4 low res, high res
n=5 low res, high res
n=6 low res, high res