fig4

Figure 4. (A) Charge density difference distribution between Zn and aniline; (B) Adsorption energies on the Zn(002) crystal plane; (C) HOMO and LUMO energy levels; (D) In-depth high-resolution XPS of C 1s and (E) N 1s. HOMO: Highest occupied molecular orbital; LUMO: lowest unoccupied molecular orbital; XPS: X-ray photoelectron spectroscopy.