surface was also investigated. The results in Table 3 reveal that the vdW correction exhibits an increase in the adsorption energies. The binding energy enhancement factor (α), which is defined as the ratio of adsorption energy with and without vdW correction, is typically ranging from 1.11 to 1.15. Moreover, a slight reduction in Fe-Cl distance up to -0.04 Å, was observed with vdW correction, which can be attributed to the ionic nature of Fe-Cl bonds, as nonlocal interactions increase the adsorption energy and reduce the Fe-Cl distances. Notably, the standard GGA-PAW method seems to overestimate the charge transfer due to not accounting for weak electrostatic interactions and dispersion forces as shown in Figure (b).