Entropy-driven docosahedral short-range order in simple liquids and glasses

The energetically favored icosahedral structure has been seen as the central figure for describing the local structure of simple liquids and glasses. Although regular icosahedral structures are rarely found, it is accepted that distorted icosahedral structures occur in simple liquids and glasses. However, which local structure dominates and why it is more frequent than the others remain unanswered questions. In this study, by using a recently developed structure descriptor, we show that docosahedral structures are the most favored not only in models of simple liquids and glasses but also in an experimental colloid glass. We also show that the the predominance of docosahedral structures is entropy-driven. Our findings represent a significant milestone towards comprehending mysterious phenomena such as supercooling, glass transition, and crystallization, where local structures play a key role.