A stable compound of helium and sodium at high pressure.

  title={A stable compound of helium and sodium at high pressure.},
  author={Xiao Dong and Artem R. Oganov and Alexander F. Goncharov and Elissaios Stavrou and Sergey S. Lobanov and Gabriele Saleh and Guang-Rui Qian and Qiang Zhu and Carlo Gatti and Volker L. Deringer and Richard Dronskowski and Xiang-Feng Zhou and Vitali B. Prakapenka and Zuzana Kon{\^o}pkov{\'a} and Ivan A. Popov and Alexander I. Boldyrev and Hui-Tian Wang},
  journal={Nature chemistry},
  volume={9 5},
Helium is generally understood to be chemically inert and this is due to its extremely stable closed-shell electronic configuration, zero electron affinity and an unsurpassed ionization potential. It is not known to form thermodynamically stable compounds, except a few inclusion compounds. Here, using the ab initio evolutionary algorithm USPEX and subsequent high-pressure synthesis in a diamond anvil cell, we report the discovery of a thermodynamically stable compound of helium and sodium… 
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