There are two Fortran 90 codes here. The main code checks.f90 uses the module defs.f90 which contains some definitions.
The codes check that the tangential component of the electric field E and the
normal component of the electric displacement D are continuous
across the lipid-water interface at z'
= 0 and across the lipid-cytosol interface at z' = -t. Here z' = z - t/2 is the z-coordinate in the asymmetrical
system of cordinates in which z' =
0 labels the lipid-water interface.