Related papers: Structural evolution in high-pressure amorphous CO…
The structures of compressed rubidium polyhydrides, RbHn with n>1, and their evolution under pressure are studied using density functional theory calculations. These phases, which start to stabilize at only P=2 GPa, consist of Rb+ cations…
We study compression of coesite to pressures above 35 GPa, substantially beyond the equilibrium transition pressure to octahedral phases (8 GPa to stishovite). Experiments at room temperature showed that up to 30 GPa the metastable coesite…
Carbon nano-onions (CNO) are multi-shell fullerenes. In the present work, we used fully atomistic reactive (ReaxFF) molecular dynamics simulations to study the dynamics and structural transformations of CNO structures under high-velocity…
We use ab initio density functional calculations to study the formation and structural as well as thermal stability of cellular foam-like carbon nanostructures. These systems with a mixed $sp^2/sp^3$ bonding character may be viewed as…
Characteristic shock effects in silica serve as a key indicator of historical impacts at geological sites. Despite this geological significance, atomistic details of structural transformations under high pressure and shock compression…
Carbon can exist as isolated dumbbell, one-dimensional (1D) chain, 2D plane, and 3D network in carbon solids or carbon-based compounds, which attributes to its rich chemical binding way, including sp-, sp2-, and sp3-hybridized bonds. Sp2…
Understanding the formation of molecules under conditions relevant to interstellar chemistry is fundamental to characterize the chemical evolution of the universe. Using reactive molecular dynamics simulations with model-based or…
We report results of MD simulations of amorphous ice in the pressure range 0 - 22.5 kbar. The high-density amorphous ice (HDA) prepared by compression of Ih ice at T = 80 K is annealed to T = 170 K at intermediate pressures in order to…
The complex crystal chemistry of elemental boron has led to numerous proposed structures with distinctive motifs as well as contradictory findings. Herein, evolutionary structure searches performed at 100 GPa have uncovered a series of…
Amorphous carbon (a-C) materials have diverse interesting and useful properties, but the understanding of their atomic-scale structures is still incomplete. Here, we report on extensive atomistic simulations of the deposition and growth of…
We study numerically an atomistic model which is shown to exhibit a one--step crystal--to--amorphous transition upon decompression. The amorphous phase cannot be distinguished from the one obtained by quenching from the melt. For a…
Results of X-ray diffraction experiments on solid oxygen at low temperature and at pressures up to 10 GPa are presented.A careful sample preparation and annealing around 240 K allowed to obtain very good diffraction patterns in the…
The formation of boron carbide under high pressures and from elemental reactants has been studied and optimum parameters have been determined by varying the (P, T, reactants) conditions. To this end, stoichiometric mixtures of commercial…
Amorphous phosphorus (a-P) has long attracted interest because of its complex atomic structure, and more recently as an anode material for batteries. However, accurately describing and understanding a-P at the atomistic level remains a…
Two-mode valence electron configuration of carbon atoms lays the foundation of the unique two-mode amorphous state of the monoatomic carbon solid. From the fundamentals of solid-state physics, sp$^3$ and sp$^2$ amorphous carbons are two…
The high-pressure II-III phase transition in solid hydrogen is investigated using the random phase approximation and diffusion Monte Carlo. Good agreement between the methods is found confirming that an accurate treatment of exchange and…
Understanding the atomic-scale structure and dynamics of amorphous oxide surfaces is essential for interpreting their chemical reactivity, mechanical stability, and interfacial behavior, yet direct experimental characterization remains…
Boron phosphide (BP) is a (super)hard semiconductor constituted of light elements, which is promising for high demand applications at extreme conditions. The behavior of BP at high temperatures and pressures is of special interest but is…
Simple binary oxide glasses can exhibit a compression behavior distinct from that of their crystalline counterparts. In this study, we employed high-pressure X-ray absorption spectroscopy coupled to the diamond anvil cell to investigate in…
We combine modeling and measurements to investigate the dynamics of convective carbon dioxide (CO$_2$) dissolution in a pressure-volume-temperature cell, extending a recent study by Wen et al. (J. Fluid Mech., vol. 854, 2018, pp. 56--87) at…