ELFT HÍRADÓ

[Szeminárium koordinátor <szfi-seminar AT wigner.hun-ren.hu>]

SZFI Seminar
Anders Nilsson
(Department of Physics, Stockholm University, Sweden, host: Pusztai László)
Accessing Waters “No-Mans Land” using X-ray Lasers
Water is of extreme importance for our society and the key component of life 
as we know it but it is also of extraordinary interest due to its remarkable 
physical properties that differ from almost all other liquids. Deviation of 
water’s properties from a simple liquid exists already in the ambient 
temperature regime and then becomes strongly enhanced upon supercooling. In 
particular, the finding that the thermodynamic response and correlation 
functions appear to diverge towards a singular temperature estimated by 
power-law fits of about 228 K has led to several hypotheses about the origin 
of waters anomalous properties. One hypothesis to explain the apparent 
divergence is that there exists a liquid-liquid transition with a 
liquid-liquid critical point at rather high positive pressures. In this 
scenario the Widom line, defined as the locus of correlation length maxima in 
the P-T plane, emanates from the critical point as a continuation of the 
liquid-liquid transition line into the one-phase region and the divergence in 
the response functions is towards this line. The challenge is that the 
temperature Ts lies below the homogeneous ice nucleation temperature 232 K, a 
region of the phase diagram that has been denoted as “no man’s land”, since 
ice crystallization occurs on much faster time scale compared to the 
experimentally accessible time scale in a typical laboratory setting.Here I 
will present how x-rays from x-ray lasers and synchrotron radiation sources 
have been used to probe the liquid phase of water from hot to the deep 
supercooled water regime inside no-man’s land. In particular, I will discuss 
if a liquid-liquid transition, Widom line, a critical point and a dynamical 
transition exists in deep supercooled water causing fluctuations all the way 
up to ambient temperature. This would open-up for that water at ambient 
conditions is in a supercritical state.  Thursday, 12 June 2025, 10:00
Wigner FK SZFI, Bldg. 1, 2nd floor auditorium
Language of the talk: English
All interested are welcome!
Attila Nagyszfi-seminar AT wigner.hun-ren.hu

Prof. Nilsson előadását követően (és ahhoz 
kapcsolódóan), várhatóan kb. 11:15-től a 
következő rövid, 20 perces előadások fognak elhangzani:-- 
Structural and order parameters in a long LDL/ HDL simulaton,    
     by BAKÓ, Imre (HUN-REN Centre for Natural 
Sciences) and TÓTH, Gergely (presenter, L. Eötvös 
University, Budapest)-- Optimizing Force Field Parameters for Calcium 
Chloride Transport: Balancing Ion-Ion and Ion-Water Interactions in Molecular 
Dynamics Simulations         by S. Shabbir 
(presenter), D. Boda and Z. Ható (Center for Natural Sciences, 
University of Pannonia, Veszprém, Hungary)-- Validating Water Models 
with Diffraction Data Across the Liquid Phase,        
 by SOCZÓ, Bálint (presenter, BSc student of the Technical 
University, Budapest) and PETHES, Ildikó (HUN-REN Wigner Research 
Centre for Physics)