Table 1: Total energy (au) values of the structures considered.

Structure RB3LYP/6–31G(d) RB3LYP/6–31G(d,p) Total energy Corrected total energy Total energy Corrected total energy A1 −1527.42 −1527.02 −1527.47 −1527.07 A2 −1527.44 −1527.04 −1527.49 −1527.10 A3 −1527.45 −1527.05 −1527.50 −1527.10 A4 −1527.44 −1527.04 −1527.49 −1527.09 A5 −1527.44 −1527.04 −1527.49 −1527.09 A6 −1527.44 −1527.04 −1527.49 −1527.10