Helicenes are an interesting class of adsorbates due to their molecular chirality, the formation of self-assembled monolayers upon adsorption on metallic substrates, the chiral polymorphism of the assembled patterns, and their intriguing optical properties. Structurally, they are highly-conjugated, ortho-fused, chiral, aromatic hydrocarbons. The chirality of helicenes, despite the lack of a chiral center, arises from the fusion of benzene rings in the ortho position, such that they adopt a chiral helical topology when the backbone is large enough to encounter steric repulsion of the two ends. As chiral PAHs, helicenes can facilitate asymmetric and enantioselective reactions, including those of biological importance, and have the ability to transfer chirality to supramolecular systems through directed self-assembly. Due to their helical backbones, helicenes generally approach the substrate through two to four terminal rings, despite significant dispersive interaction of the entire backbone to the surface. As a result, some of the molecular structure flattens when adsorbed, and subsequent deformations propagate through the entire backbone. A good understanding of the interaction of the terminal rings with the surface is thus essential in developing insight into stereochemical recognition within the self-assembled structure. On the other hand, the structure of coronene (denoted below as [6]C) can also be interpreted as an ortho-fused six-ring PAH (analogous with hexahelicene [6]H), but with the ends fused together. Coronene exhibits a planar structure, maximizing dispersive interactions on flat, pristine metallic substrates. This, combined with the similar footprint of [6]C and [6]H, makes [6]C a good reference for studies pertaining to helicene adsorption on metal substrates. As a large planar PAH, coronene has been well studied in its own right as a model for graphene sheets and related nanomaterials. Surface functionalization with helicenes, as well as other PAHs, is a promising approach for fabrication of new materials with interesting opto-electronic properties, as well as possible advancements in chiral separations. Considerable work has been conducted on the self-assembly behaviour of helicenes on coinage metal substrates, with much of the discussion focusing on adsorption on perfectly symmetrical (pristine) substrates. The deposition and chiral transfer mechanisms in helicene adsorption have been studied extensively for a series of helicenes on several metallic surfaces by Ernst et al, and others. Chiral deposition outcomes were found to be strongly influenced by the choice of metallic substrate in these systems: On Cu(111), multi-level enantiomorphism is observed, with racemic mixtures of heptahelicene assembled in homochiral trimer and hexamer patterns, which form parallel rows with mirror-image symmetry; On Ni(111), despite its similarity with the Cu(111) lattice, molecules adsorbed strongly but no enantiomorphism is observed, likely because of the adsorbates' lack of mobility once adsorbed; 29 weakly-binding Ag(111) and Au(111) substrates exhibit local chiral recognition for heptahelicene but no long range enantiomorphism, likely due to their lattice mismatch to the helicene backbone and the resulting stress building up in the monolayer pattern. Our group has recently performed computational investigations of the behaviour of helicene monomers and stacked dimers on pristine (111) coinage metal substrates. We found that single helicene molecules bound more strongly to Cu(111) than Ag(111) and Au(111) substrates, and that [6]C was able to bind more efficiently due to greater dispersive interactions with the underlying substrate. A strong flattening of the three surface-adjacent rings was observed, in agreement with work by Ernst et al . Deposition of further molecules led to preferentially homochiral arrangements in both lateral and stacked configurations, with stacked configurations deforming the surface-supported molecule in the most favorable binding configurations. Similar behaviour was observed for [5]H, [6]H, and [7]H. The findings of our study served to indicate, in conjunction with experimental findings on monolayer and multilayer chirality behaviour, that small changes at the single molecule level may have vast implications for the behavior of the mixed monolayer. The question of how the behavior of helicenes changes in the vicinity of surface defects thus becomes important to address. In this work, we decorate coinage metal substrates with metallic adatoms, in order to better understand the interactions of helicenes on more realistic substrates. We chose the intermediate-length molecule, [6]H, for this follow-up study, as its behaviour in single-or two-molecule deposition presented similar characteristics to both [5]H and [7]H. Herein, we examine [6]H monomers and dimers, as well as [6]C, as a planar reference molecule, on Au(111) and Cu(111) substrates with one to four adatoms, using computational chemistry.