Here is a fully simplified version of my Shamrock Box. The original was based on a molecule which can easily be tessellated. However, with a single molecule used for a box, there is no need to connect multiple molecules, and the model can be simplified. Later, I found a way to tessellate the simplified shamrock anyway with just a slight modification.
Have a look at the [comparison]((/models/shamrock-box-simplified-variants) of this model with the slightly simplified variant.