Novel phase of beryllium fluoride at high pressure

Abstract

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 contains 18 atoms in the primitive unit cell. Given the analogy between BeF${}_2$ and SiO${}_2$, silica phases have been investigated as well, but the new phase has not been observed to be thermodynamically stable for this system. However, it is found to be metastable and to have comparable energy to the known metastable phases of SiO${}_2$, suggesting a possibility of its synthesis.

6 pages, 7 figures

References in corpus (3)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Intrinsic Correlation between Hardness and Elasticity in Polycrystalline Materials and Bulk Metallic Glasses
• Superionicity and Polymorphism in Calcium Fluoride at High Pressure

Cited by in corpus (3)

• High-pressure phases of group II difluorides: polymorphism and superionicity
• A first-principles investigation of the linear thermal expansion coefficients of BeF${}_2$: Giant thermal expansion
• Structural evolution of amorphous polymeric nitrogen from \textit{ab initio} molecular dynamics simulations and evolutionary search