相关论文: A stable compound of helium and sodium at high pre…
Helium (He) is the most inert noble gas at ambient conditions. It adopts a hexagonal close packed structure (P63/mmc) and remains in the insulating phase up to 32 TPa. In contrast, lithium (Li) is one of the most reactive metals at zero…
At ambient pressure, sodium, chlorine, and their only known compound NaCl, have well-understood crystal structures and chemical bonding. Sodium is a nearly-free-electron metal with the bcc structure. Chlorine is a molecular crystal,…
The only known compound of sodium and hydrogen is archetypal ionic NaH. Application of high pressure is known to promote states with higher atomic coordination, but extensive searches for polyhydrides with unusual stoichiometry remain…
Recently for the first time a stable compound of He and Na (Na2He) is predicted at high pressure. We explore the pressure dependent elastic, mechanical and thermodynamic properties of this newly discovered Na2He by using ab initio…
Helium and rare gases (RG: Ne, Ar, Kr, Xe) are typically considered chemically inert, yet under the extreme pressures of planetary interiors they may form compounds with unexpected properties. Using crystal structure prediction and…
We demonstrate in this paper that high pressure can promote the reactions between the ionic compounds and H2 molecules and form thermodynamically stable hybrid compounds. Using crystal structure search method based on first principles…
HCl, a 'textbook' example of a polar covalent molecule, is a well-known compound of hydrogen and chlorine. Inspired by the discovery of unexpected stable stoichiometries of sodium chlorides, we performed systematic searches for all stable…
Sodium chloride (NaCl), or rocksalt, is well characterized at ambient pressure. Due to the large electronegativity difference between Na and Cl atoms, it has highly ionic chemical bonding, with stoichiometry 1:1 dictated by charge balance,…
We investigate the binary phase diagram of helium and iron using first-principles calculations. We find that helium, which is a noble gas and inert at ambient conditions, forms stable crystalline compounds with iron at terapascal pressures.…
The simple alkali metal Na, that crystallizes in a body-centred cubic structure at ambient pressure, exhibits a wealth of complex phases at extreme conditions as found by experimental studies. The analysis of the mechanism of stabilization…
The application of high pressure can fundamentally modify the crystalline and electronic structures of elements as well as their chemical reactivity, which could lead to the formation of novel materials. Here, we explore the reactivity of…
We report the formations of fcc and distorted hcp iron-helium compounds with x in FeHex up to 0.13 and 0.48, respectively, based on experiments at 5-54 GPa and ~1000-2820 K. Upon releasing pressure under room temperature, these fcc and…
The metal-based noble gas compounds exhibit interesting behavior of electronic valence states under pressure. For example, Xe upon compression can gain electrons from the alkali metal, or lose electrons unexpectedly to Fe and Ni, toward…
Uranium is considered as a very important nuclear energy material because of the huge amount of energy released. As the main products of spontaneous decay of uranium, helium is difficult to react with uranium for its chemical inertness.…
A growing body of theoretical and experimental evidence suggests that inert gases (He, Ne, Ar, Kr, Xe, Rn) become less and less inert under increasing pressure. Here we use the ab initio evolutionary algorithm to predict stable compounds of…
The search of direct-gap Si-based semiconductors is of great interest due to the potential application in many technologically relevant fields. This work examines the incorporation of He as a possible route to form a direct band gap in Si.…
A previously unknown thermodynamically stable high-pressure phase of BeF$_{2}$ has been predicted using the evolutionary algorithm USPEX. This phase occurs in the pressure range 18-27 GPa. Its structure has $C2/c$ space group symmetry and…
Early quantum mechanical models suggested that pressure drives solids towards free-electron metal behavior where the ions are locked into simple close-packed structures. The prediction and subsequent discovery of high-pressure electrides…
We used our developed AI search engine~(InvDesFlow) to perform extensive investigations regarding ambient stable superconducting hydrides. A cubic structure Li$_2$AuH$_6$ with Au-H octahedral motifs is identified to be a candidate. After…
Hydrogen-rich compounds hold promise as high-temperature superconductors under high pressures. Recent theoretical hydride structures on achieving high-pressure superconductivity are composed mainly of H2 fragments. Through a systematic…