Fully relativistic study of intermetallic dimers of group-1 elements K through element 119 and prediction of their adsorption on noble metal surfaces

► Fully relativistic 4c-DFT calculations were performed for M2 and MAu (M = K though element 119). ► Trends in atomic and molecular properties are reversed in group 1 from Cs on due to relativity. ► The 8s(119) AO stabilization and contraction result in the weakest M-Au bond in group 1. ► The weakest adsorption of element 119 on noble metals is expected among all group-1 elements.