DFT, Fukui indices, and molecular dynamic simulation studies on corrosion inhibition characteristics: a review

The density functional theory (DFT), a well-known tool, can be employed to predict the high electron density position and HOMO–LOMO difference in energy in the inhibitor structure which has a high probability of donating electrons to the metal surface. Fukui functions are connected to the Frontier orbital theory (also known as the Fukui theory of reactivity and selection) and describe how nucleophiles target the highest occupied orbital (HOMO) while depositing their excess electrons in the lowest unoccupied orbital (LUMO). However, it is insufficient for predicting the corrosion inhibition mechanism occurring on the metal surface, such as the adsorption position of the inhibitor on the metal surface to form an adsorption layer. Hence, molecular dynamic (MD) simulation is a reliable method to better understand the interaction and adsorption behaviour of an inhibitor on the metal surface. MD was explored in the phase-related adsorption of the solution. The RDF can be used to identify the average interaction distance along with the number of metal atoms that are within a particular distance of the inhibitor molecule. It can be used to identify the type of adsorption. Hence, this review is focused on the compilation and brief elaboration of the DFT, Fukui indices, MD simulation, and RDF findings for the corrosion inhibition mechanisms. Graphical abstract