We therefore wish to validate our results for the (COF1) 2 dimer model using larger model systems, and to that end we next consider dimers of the three monomer units in Fig. . These were constructed from the basic COF-1 monomer in Fig. , without further optimization. The "half-COF1" structure in Fig. represents half of the monomer unit in Fig. and its smaller size allows us to examine basis-set and size effects.