ELFT HÍRADÓ

[Szeminárium koordinátor <sem-admin AT szfki.hu>]

SZFI SeminarPusztai LászlóHUN-REN Wigner RCP SZFIVízállásjelentés: mit 
tud(hat...)unk a víz atomi szintű folyadékszerkezetéről?  (Water level 
report: what do(/can...) we know about the microscopic structure of liquid 
water?)Tuesday, 6 May 2025, 10:00, KFKI Campus, Bldg. 1, 2nd floor, 
Conference RoomWater is undoubtedly the most important liquid on our planet, 
as well as in our everyday life. Due to this fact, a huge amount of 
information has been gathered about its properties, from the isolated 
molecule/small groups of molecules to large bulks of the liquid, such as the 
oceans. In this presentation, I will focus on the atomic level structure of 
bulk liquid water: the reason is that the most essential characteristic, 
hydrogen bonding (H-bonding), has the most profound effect in this form -- 
and also, that there are still controversies concerning the basics of the 
microscopic structure.I will briefly mention the so-called 'water anomalies', 
of which the best known is that water molecules naturally form a liquid phase 
under ambient conditions. Another well-known anomaly is the density maximum 
at 4 degrees C (which in itself has a major effect on life in natural 
waters). All the ca. 50 anomalies are due to the presence of the 
aforementioned peculiarity: hydrogen bonding.I will elaborate on the problems 
with determining the most basic quantity, the first non-bonding O...H 
distance (the H-bonding distance). The intrinsic severe difficulties with 
neutron diffraction experiments, that should be sensitive to this distance, 
will be explained in some detail, along with efforts that have been made by 
the speaker over the past 25 years or so (see, e.g., [1]).In the last section 
of the presentation, the possible exploitation of polarised neutron 
diffraction will be shown (see, e.g., [2]). [1] L. Pusztai, Phys. Rev. B 60, 
11851 (1999)[2] L. Temleitner, A. Stunault, G. Cuello, L. Pusztai, Phys. Rev. 
B 92, 014201/1-6 (2015)  Minden érdeklődőt szívesen látunk! - Everyone 
is welcome to attend.Attila Nagysem-admin AT szfki.hu