Abstract:
Hafnium hydrogen compounds have recently become the vibrant materials for structural prediction at
high pressure, from their high potential candidate for high-temperature superconductors. In this work,
we predict HfH6 by exploiting the evolutionary searching. A high-pressure phase adopts a sodalite-like
clathrate structure, showing the body-centered cubic structure with a space group of Im3¯m. The frstprinciples calculations have been used, including the zero-point energy, to investigate the probable
structures up to 600GPa, and fnd that the Im3¯m structure is thermodynamically and dynamically
stable. This remarkable result of the Im3¯m structure shows the van Hove singularity at the Fermi level
by determining the density of states. We calculate a superconducting transition temperature (Tc) using
Allen-Dynes equation and demonstrated that it exhibits superconductivity under high pressure with
relatively high-Tc of 132 K.
