Polytypism-induced stabilization of hexagonal 2H, 4H and 6H phases of gold

Recent experiments reveal that, contrary to traditional expectations, face-centered cubic Gold known, in many respects, as the “noblest” of all metals evincing remarkable repertoire of chemistry, can adopt in the nano-scale regime unusual hexagonal close-packed polytypes (2H, and 4H) form. Through first-principles study, we show evidence of global phase stability (via thermodynamic, mechanic and dynamic calculations) of the synthesized 2H and 4H with distinguished structural correspondence to experimental measurements. In addition, we found that polytypism can induce stable higher polytype hexagonal 6H phase of Au.