相关论文: Structural transformation between long and short-c…
The anomalous $\lambda$-transition of liquid sulfur, which is supposed to be related to the transformation of eight-membered sulfur rings into long polymeric chains, has attracted considerable attention. However, a detailed description of…
First-order phase transitions are characterized by a discontinuous first derivative of the Gibbs free energy, so that volumes and entropies are discontinuous. Such transitions are common in the crystalline state, but extremely rare in…
We report results of ab initio constant-pressure molecular dynamics simulations of sulfur compression leading to structural transition and pressure-induced amorphization. Starting from the orthorhombic S-I phase composed of S$_8$ ring…
Using molecular dynamics simulations driven by a machine-learned interatomic potential, we investigate at low to intermediate pressures the $\lambda$-transition of sulfur, a temperature-induced polymerization. At ambient pressure, we…
The existence of a 'crossover region' in glass-forming liquids has long been considered as a general phenomenon that is as important as the glass transition. One potential origin for the crossover behavior is a liquid-to-liquid phase…
We report here a study of reversible pressure-induced structural transformation between two amorphous forms of SO$_2$: molecular at pressures below 26 GPa and polymeric above this pressure, at temperatures of 77 - 300 K. The transformation…
We report density-functional based molecular dynamics simulations, that show that, with increasing pressure, liquid carbon undergoes a gradual transformation from a liquid with local three-fold coordination to a 'diamond-like' liquid. We…
We report results of molecular dynamics simulations of liquid water at the temperature T=277 K for a range of high pressure. One aim of the study was to test the model Amoeba potential for description of equilibrium structural properties…
Molecular dynamics simulation studies were performed to investigate the structural and dynamic properties of liquid carbon disulfide from ambient to elevated pressure conditions. The results obtained have revealed structural changes at high…
A structural transformation in water upon compression was recently observed at the temperature $T=277$~K in the vicinity of the pressure $p \approx 2\;000$~Atm [R.M. Khusnutdinoff, A.V. Mokshin, J. Non-Cryst. Solids \textbf{357}, 1677…
Recent experimental results indicate that phosphorus, a single-component system, can have two liquid phases: a high-density liquid (HDL) and a low-density liquid (LDL) phase. A first-order transition between two liquids of different…
Acoustical measurements, electron spin resonance, and Raman spectroscopy have been employed to probe sulfur over the temperature range 80 to 180 C, which includes the polymerization transition and the supercooled liquid state. Acoustical…
It has recently been shown that the TIP4P/Ice model of water can be studied numerically in metastable equilibrium at and below its liquid-liquid critical temperature. We report here simulations along a subcritical isotherm, for which two…
Sulfur was the first nonmetal element which was transformed to a superconductor by applying megabar pressure. Recent pioneering experimental developments in measuring the superconducting energy gap $\Delta(T)$ in compressed sulfur using…
We have mapped the molecular-atomic transition in liquid hydrogen using first principles molecular dynamics. We predict that a molecular phase with short-range orientational order exists at pressures above 100 GPa. The presence of this…
Recent research suggests that the supercritical state consists of liquidlike and gaslike states where particle dynamics and key system properties are qualitatively different. We report experimental evidence of the structural crossover in…
The study of liquid-liquid phase transition has attracted considerable attention. One interesting example of such phenomenon is phosphorus for which the existence a first-order phase transition between a low density insulating molecular…
There have been ample studies of the many phases of H2O in both its solid and low pressure liquid states, and the transitions between them. Using molecular dynamics simulations we address the hitherto unexplored deeply supercritical…
This chapter overviews sulfur chemical speciation and behavior in different types of hydrothermal fluids across the lithosphere, spanning from active geothermal systems to basinal brines, to metamorphic and magmatic-hydrothermal fluids. The…
We use numerical simulation to examine the possibility of a reversible liquid-liquid transition in supercooled water and related systems. In particular, for two atomistic models of water, we have computed free energies as functions of…