Multistep Dissociation of Fluorine Molecules under Extreme Compression

Abstract

All elements that form diatomic molecules, such as H 2 , N 2 , O 2 , Cl 2 , Br 2 , and I 2 are destined to become atomic solids under sufficiently high pressure. However, as revealed by many experimental and theoretical studies, these elements show very different propensity and transition paths, due to the balance of reduced volume, lone pair electrons, and interatomic bonds. The study of F under pressure can illuminate this intricate behavior since F, owing to its unique position on the periodic table, can

Estimation of suitable upper-limits for temperature, in stability comparisons between solid phases at high pressures. Study cases: carbon, oxygen, and fluorine

“…For the solid phases of fluorine, detailed calculations were carried in the same pressure range as for oxygen, with its two most stable structures (Olson et al, 2020;Duan et al, 2021): Cmca and Pm3n, using a projector-augmented wave pseudopotential with seven explicit valence electrons. The k-point grids for the Brillouin zone integration were also generated using the Monkhorst-Pack method with sizes 16 × 16 × 16 for both Cmca and Pm3n.…”

Polymeric Hydronitrogen N4H: A Promising High-Energy-Density Material and High-Temperature Superconductor

“…The plane-wave kinetic energy cutoff is set as 60 Ry. The superconducting transition temperature is calculated by solving the McMillan–Allen–Dynes equation − as below T normalc = ω log 1.2 exp [ − 1.04 false( 1 + λ false) λ false( 1 − 0.62 μ * false) − μ * ] where μ* is the Coulomb pseudopotential and ω log is the logarithmic average of the phonon frequency.…”

High-pressure stabilization of open–shell bromine fluorides

“…However, compression leads to substantial alteration of the bonding pattern of these elements, as evidenced by the molecular dissociation of iodine and bromine, 8,9 or the predicted polymerization of fluorine. 10,11 These structural transformations present a fascinating and still not fully explored area of research. The chemical reactivity of halogen-rich materials at large compression is an even less investigated matter; however, it is the one that is drawing more and more attention.…”