10.1021/acs.inorgchem.7b01686.s001
Xiaofeng Li
Xiaofeng
Li
Feng Peng
Feng
Peng
Superconductivity of Pressure-Stabilized Vanadium
Hydrides
American Chemical Society
2017
H-rich V hydrides
first-principles structure searches
H 2 molecules
Pressure-Stabilized Vanadium Hydrides
coordination number
VH 8
VH 5
2017-11-02 15:49:32
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Superconductivity_of_Pressure-Stabilized_Vanadium_Hydrides/5563117
The study of the high-temperature
superconductive property in compressed hydrogen (H)-rich hydrides
has been motivated by hydrides, which become superconducting at low
pressure due to chemical precompression. In the present study, we
report the first-principles structure searches for stable vanadium(V)
hydrides over a pressure scope 0–200 GPa, where stable unexpected
stoichiometries of H-rich V hydrides (e.g., VH<sub>3</sub>, VH<sub>5</sub>, and VH<sub>8</sub>) emerge. These dense H-rich V hydrides
are metallic with a strong ionic feature, and the coordination number
of metal V gradually increases with H content. In particular, <i>C</i>2/<i>m</i>-VH<sub>8</sub>, which consists of
infinite zigzag chains of sole H<sub>2</sub> molecules, has the highest
coordination number of 16. From our electron–phonon calculations,
one can see that <i>P</i>6<sub>3</sub>/<i>mmm</i>-VH<sub>5</sub> and <i>C</i>2/<i>m</i>-VH<sub>8</sub> are superconductors with estimated superconducting temperatures
(<i>T</i><sub>c</sub>) of 18.5 and 71.4 K at 200 GPa, respectively.
Our simulations not only uncovered the crystal structures of V hydrides,
but also established the high-temperature superconductive nature of
them.