Journal Article

PUBDB-2017-00938

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png A stable compound of helium and sodium at high pressure

Dong, X. ; Oganov, A. R. (Corresponding author) ; Goncharov, A.Extern* ; Stavrou, E.Extern* ; Lobanov, S.Extern* ; Saleh, G. ; Qian, G.-R. ; Zhu, Q. ; Gatti, C. ; Deringer, V. L. ; Dronskowski, R.Extern* ; Zhou, X.-F. (Corresponding author) ; Prakapenka, V. B. ; Konôpková, Z.XFEL.EU*DESY* ; Popov, I. A. ; Boldyrev, A. I. ; Wang, H.-T. (Corresponding author)

2017
Nature Publishing Group London

This record in other databases:        

Please use a persistent id in citations: doi:10.1038/nchem.2716

Abstract: 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, Na$_2$He, which has a fluorite-type structure and is stable at pressures >113 GPa. We show that the presence of He atoms causes strong electron localization and makes this material insulating. This phase is an electride, with electron pairs localized in interstices, forming eight-centre two-electron bonds within empty Na$_8$ cubes. We also predict the existence of Na$_2$HeO with a similar structure at pressures above 15 GPa.

---

Contributing Institute(s):

1. DOOR-User (DOOR)
2. Experimentebetreuung PETRA III (FS-PE)

Research Program(s):

1. 6G3 - PETRA III (POF3-622) (POF3-622)
2. 6211 - Extreme States of Matter: From Cold Ions to Hot Plasmas (POF3-621) (POF3-621)

Experiment(s):

1. PETRA Beamline P02.2 (PETRA III)

Appears in the scientific report 2017

---

Database coverage:
; BIOSIS Previews ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF >= 25 ; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

---