The DFT geometry optimization was performed in the DMol 3 module of Materials Studio at the GGA PBE level and using a DNP basis set with effective core potentials. In GA, the acceptable variations for convergence in geometry optimization were set as 0.01255 kcal/mol in energy, 2.510 kcal/(mol Å) in force and 0.005 Å in displacement. However, stable structures were re-optimized with tighter criteria: 0.006275 kcal/mol in energy and 0.6275 kcal/(mol Å) in force, for a more reliable population analysis.