2011/06/24 by Kjartan Thor Wikfeldt, Wikfeldt, K. T., Anders Nilsson +3 · 2 citations
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Material Dynamics and Properties #Phase Equilibria and Thermodynamics #Soft Condensed Matter (cond-mat.soft) #Spectroscopy and Quantum Chemical Studies
paper · pdf · doi:10.48550/arxiv.1106.5038
openalex publication_date 2011/06/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In the supercooled regime at elevated pressure two forms of liquid water, high-density (HDL) and low-density (LDL), have been proposed to be separated by a coexistence line ending at a critical point, but a connection to ambient conditions has been lacking. Here we perform large-scale molecular dynamics simulations and demonstrate that the underlying potential energy surface gives a strictly bimodal characterization of the molecules at all temperatures as spatially inhomogeneous either LDL- or HDL-like with a 3:1 predominance for HDL at ambient conditions. The Widom line, indicating maximum fluctuations, coincides with a 1:1 distribution. Our results indicate a unified description of liquid water covering supercooled to ambient conditions in agreement with recent x-ray spectroscopy and scattering data.