Is It Possible to Follow the Structural Evolution of Water in "No-Man's Land" Using a Pulsed-Heating Procedure?

Author(s)

Ribeiro, Ingrid de Almeida ; de Koning, Maurice ; Molinero, Valeria

• Document type: Journal article
• Source: Journal of Physical Chemistry Letters; v. 13, n. 4, p. 5-pg., 2022-02-03.

Abstract

The anomalous increase in compressibility and heat capacity of supercooled water has been attributed to its structural transformation of into a four-coordinated liquid. Experiments revealed that kappa(T) and C-p peak at T-W(thermo) approximate to 229 K [Kim et al. Science 2017, 358, 1589; Pathak et al. Proc. Natl. Acad. Sci. 2021, 118, e2018379118]. Recently, a pulsed heating procedure (PHP) was employed to interrogate the structure of water, reporting a steep increase in tetrahedrality around T-W(PHP) = 210 +/- 3 K [Kringle et al. Science 2020, 369, 1490]. This discrepancy questions whether water structure and thermodynamics are decoupled, or if the shift in T-W is an artifact of PHP. Here we implement PHP in molecular simulations. We find that the stationary states captured at the bottom of the pulse are not representative of the thermalized liquid or its inherent structure. Our analysis reveals a temperature-dependent distortion that shifts T-W(PHP) to similar to 20 K below T-W(thermo). We conclude that 2 orders of magnitude faster rates are required to sample water's inherent structure with PHP. (AU)

• FAPESP's process: 16/23891-6 - Computer modeling of condensed matter
• Grantee: Alex Antonelli
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/08293-7 - CCES - Center for Computational Engineering and Sciences
• Grantee: Munir Salomao Skaf
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC