1. Go to the

Here there is 2D+2D→3D polycatenation of (201) and (201) two-periodic nets with dihedral angle 77.4°. The planes cross through the line [010].

2. Draw the catenating nets in IsoCryst.

3. Simplify the structure removing the 2-coordinated nodes. Run ADS with the

4. A more detailed classification could be done running ADS on the fully simplified

You see here that there are listed two kinds of possible ring links, only one is Hopf. If you draw them you will see the difference, on the left the 4-4 Non-Hopf, on the right the 4-4 Hopf link:

In the Tint file data window select the following:

Use

Moreover from the picture we can see that the square intersect diagonal-diagonal (