Figure 6. a) Natural bonding orbital ; b) natural antibonding orbital ; c) result of the interaction between the two orbitals, modeling the +M effect in A17

From

Substituent Effect on Intramolecular Hydrogen Bond and Electronic Structure of E)-2-(1H-Benzo[D]Imidazol-2-Yl)-3-Phenylacrylonitrile Derivatives: QTAIM and NBO Study

Adenidji Ganiyou, Kicho Denis Yapo, Doumadé Zon, Mamadou Guy-Richard Kone, Boka Robert N’guessan

Journal of Materials Physics and Chemistry. 2019, 7(1), 8-19 doi:10.12691/jmpc-7-1-2