We present a comprehensive molecular dynamics (MD) and topological data analysis (TDA) study of liquid copper structure and transport properties at supercritical pressure. Contrary to expectations that viscosity decreases monotonically with temperature approaching 10 -5 Pas Angell, 1995, we observe an anomalous viscosity increase at high temperatures. This behavior correlates with fundamental changes in local atomic topology and medium-range order. Using persistent homology (PH) to characterize 1-dimensional holes (H 1 ) and 2-dimensional voids (H 2 ), combined with pair and radial distribution functions (PDFs, RDFs) and coordination number analysis, we reveal significant structural reorganization between 5000 K and 10000 K at 100 kbar (10 GPa). Shannon entropy increases by 14-15% for both H 1 and H 2 features above the Frenkel line, indicating a transition from the liquid-like to gas-like dynamics while maintaining high interatomic coordination. Our results demonstrate that this transition represents a genuine transition in both transport properties and topological structure in supercritical metallic liquids.
Ferracina et al. (2026) studied this question.