) where ⃗ r ab is the vector from the central node a to neighbouring node b that has components x ab and y ab ; the vector ⃗ r ac has similar meaning for the a to c edge. The defect-containing graphs were converted into polymers, and the polymer arrangements energetically minimised using LAMMPS's implementation of the Polak-Ribiere Conjugate Gradient method . More information about the conversion to polymers algorithm can be found in the Supplementary Information.