In Fig. 1, we have shown partial structure of the optimized BC3 sheet, where two types of bonds namely B C, and C C can be identified, with corresponding lengths of 1.56, and 1.42A˚ , respectively.
In order to obtain the stable configurations (local minima) of single H2CO adsorbed on the BC3 sheet, various possible initial adsorption geometries including single (hydrogen, carbon or oxygen), double (H C or C O) and triple (H C H or H C O) bonded atoms, which
are close to B and C atoms, are considered