Synthesis of Weaire-Phelan Barium Polyhydride.

J Phys Chem Lett

Centre for Science at Extreme Conditions and School of Physics and Astronomy, University of Edinburgh, Edinburgh EH8 8AQ, U.K.

Published: May 2021

By combining pressures up to 50 GPa and temperatures of 1200 K, we synthesize the novel barium hydride, BaH, stable down to 27 GPa. We use Raman spectroscopy, X-ray diffraction, and first-principles calculations to determine that this compound adopts a highly symmetric structure with an unusual 5:1 hydrogen-to-barium ratio. This singular stoichiometry corresponds to the well-defined type-I clathrate geometry. This clathrate consists of a Weaire-Phelan hydrogen structure with the barium atoms forming a topologically close-packed phase. In particular, the structure is formed by H and H clathrate cages showing substantially weakened H-H interactions. Density functional theory (DFT) demonstrates that cubic BaH requires dynamical effects to stabilize the H and H clathrate cages.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jpclett.1c00826DOI Listing

Publication Analysis

Top Keywords

clathrate cages
8
synthesis weaire-phelan
4
weaire-phelan barium
4
barium polyhydride
4
polyhydride combining
4
combining pressures
4
pressures gpa
4
gpa temperatures
4
temperatures 1200
4
1200 synthesize
4

Similar Publications

A Zn-coordinated porphyrinic artificial solid-electrolyte interphase (αSEI) layer, named [Zn]PP-4COO-(Zn), was developed to improve the reversibility of zinc metal plating/stripping in aqueous zinc-ion batteries (ZIBs). Inspired by nitrogen-terminating sites of biological molecules coordinating and transporting zinc in zinc metabolic processes, the αSEI layer was designed with zinc ions connecting porphyrinic building blocks to form two-dimensional clathrate sheets and stacking -plane sheets along the -axis to allow N cages to align and form porphyrinic N channels for zinc transport. The [Zn]PP-4COO-(Zn) αSEI layer was Zn-conductive and structurally durable during repeated stripping/plating.

View Article and Find Full Text PDF

Electric Field Influence on CO Clathrate Hydrates.

J Phys Chem A

November 2024

Department of Physics, Sikkim University, Samdur, East Sikkim 737102, India.

We consider carbon monoxide (CO) confined in the hydrogen-bonded building blocks of sI and sII clathrate hydrates, viz., (5, 56, 56) cages, within the density functional theory-based calculations. We study their response to the applied electric fields in terms of changes in the geometrical parameters, dipole moment, HOMO-LUMO gap, and vibrational frequency shift.

View Article and Find Full Text PDF
Article Synopsis
  • Ongoing research is focused on safely storing and utilizing hydrogen as a fuel alternative to carbon-based sources, but challenges like high energy costs due to its low density complicate this goal.
  • Clathrates, or gas hydrates, form when hydrogen is trapped in water molecules, providing a potential solution for safely storing hydrogen as they only require water to create these structures.
  • A proposed solution involves using hydrophobic mesoporous silica as a host material, which allows for hydrogen storage at lower pressures and temperatures, showing about a 20% reduction in required pressure for formation compared to traditional methods, with further insights gained from neutron scattering techniques.
View Article and Find Full Text PDF

Bjerrum defects in s-II gas hydrate.

J Mol Graph Model

December 2024

Department of Chemistry, Süleyman Demirel University, 32260 Isparta, Turkey. Electronic address:

Article Synopsis
  • The study explores the energy and structural characteristics of Bjerrum defects in structure II gas hydrates using advanced computational methods.
  • It finds that these defects can influence the stability and behavior of guest molecules, like THF, within the hydrate structure by forming hydrogen bonds.
  • The research challenges previous understandings by indicating that guest-induced Bjerrum defects involve both L and D components, providing new insights that could affect the interpretation of related experimental properties.
View Article and Find Full Text PDF

This perspective outlines recent developments in the field of NMR spectroscopy, enabling new opportunities for in situ studies on bulk and confined clathrate hydrates. These hydrates are crystalline ice-like materials, built up from hydrogen-bonded water molecules, forming cages occluding non-polar gaseous guest molecules, including CH, CO and even H and He gas. In nature, they are found in low-temperature and high-pressure conditions.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!