Agenda
Histórico

23 de novembro de 2026
14h00
Anfiteatro Verde (IFSC-USP)

Maurice de Koning
Instituto de Física Gleb Wataghin
Universidade Estadual de Campinas

Water Under Extreme Conditions: Unusual Phases and Phase Transitions

Water is one of the most familiar substances in nature, yet its behavior under extreme pressures and temperatures is remarkably complex. Under conditions encountered deep inside giant planets, water can enter a so-called superionic state, in which oxygen atoms form a crystalline lattice while hydrogen ions remain highly mobile. This unusual combination of solid-like and liquid-like behavior gives rise to a rich variety of phases and phase transitions. In this talk, I will discuss how molecular dynamics simulations and free-energy calculations can be used to investigate the behavior of water under these extreme conditions. I will present our recent work on the thermodynamic stability of different phases of dense water and the microscopic mechanisms underlying transformations between them. Particular attention will be given to the interplay between the motion and structural organization of hydrogen and oxygen, and to the role of transformation kinetics and microstructure in determining the resulting behavior.