The similarity of the M- [6]H and P - [6]H binding energies, despite the structural complexity of the adsorption motif, prompted our examination of the relative stability of various adsorbed conformations. Binding energies for the two enantiomers in different orientations on the three-adatom and four-adatom surfaces are shown in Table . The adsorption strength of the monomer varies depending on the initial rotational orientation of the molecule relative to the adatom structure. As expected, the system lands in different minima, depending on the initial molecule-surface orientation, as the zero-Kelvin optimizations are unable to fully sample the conformational space. The most stable and least stable adsorbed conformations of the two enantiomers are presented in Figures and. The most stable conformations share structural similarities: the helicene molecules are consistently centered over the adatoms in each of the low-energy arrangements. Favourable overlap of three or four adsorbate rings with three adatoms leads to stronger interaction, resulting in low molecule-surface distance. Although we did not study barrier heights, these structures would all be competitive at room temperature. The strongly-bound helicene molecules experience different molecular coiling in the vicinity of adatom substrates than when deposited on the pristine surface: on the pristine surface, rings near the surface flatten, increasing coiling in the region of the molecule distant from the surface. On surfaces with defects, the adatoms present a smaller attractive "span", leading to less flattening of the rings near the substrate, and thus less coiling of the upper rings. As a result, the overall ring heights (and thus the degree of coiling) of the strongly adsorbed helicene conformations are in the middle range of molecular heights for all the configurations considered here, despite their strong molecule-surface interactions (for example, the curves corresponding to 30°, Figure ). for four adatoms.