We report first-principle based studies of element 113 (E113) interactions with gold aimed primarily at estimating the adsorption energy in thermochromatographic experiments. The electronic structure of E113-Aun systems was treated within the accurate shape-consistent small core relativistic pseudopotential framework at the level of non-collinear relativistic density functional theory (RDFT) with specially optimised Gaussian basis sets. We used gold clusters with up to 58 atoms to simulate the adsorption site on the stable Au(111) surface. Stabilization of the E113-Aun binding energy and the net Bader charge of E113 and the neighboring Au atoms with respect to n indicated the cluster size used was appropriate. The resulting adsorption energy estimates lie within the 1.0–1.2 eV range, substantially lower than previously reported values.