Unusually complex phase of dense nitrogen at extreme conditions
Here, nitrogen exhibits an exceptional polymorphism under extreme conditions, making it unique amongst the elemental diatomics and a valuable testing system for experiment-theory comparison. Despite attracting considerable attention, the structures of many high-pressure nitrogen phases still require unambiguous determination. Here, we report the structure of the elusive high-pressure high-temperature polymorph ι–N 2 at 56 GPa and ambient temperature, determined by single crystal X-ray diffraction, and investigate its properties using ab initio simulations. We find that ι–N 2 is characterised by an extraordinarily large unit cell containing 48 N 2 molecules. Geometry optimisation favours the experimentally determined structure and density functional theory calculations find ι–N 2 to have the lowest enthalpy of the molecular nitrogen polymorphs that exist between 30 and 60 GPa. The results demonstrate that very complex structures, similar to those previously only observed in metallic elements, can become energetically favourable in molecular systems at extreme pressures and temperatures.
- Authors:
-
[1] ; [2];
[3] ; [1];
[4] ; [1]; [3];
[5]
- Univ. of Edinburgh, Edinburgh (United Kingdom)
- European Synchrotron Radiation Facility, Grenoble (France)
- Center for High Pressure Science & Technology Advanced Research, Shanghai (China)
- Univ. of Edinburgh, Edinburgh (United Kingdom); SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Chinese Academy of Sciences, Hefei (China)
- Publication Date:
- Grant/Contract Number:
- AC02-76SF00515
- Type:
- Accepted Manuscript
- Journal Name:
- Nature Communications
- Additional Journal Information:
- Journal Volume: 9; Journal Issue: 1; Journal ID: ISSN 2041-1723
- Publisher:
- Nature Publishing Group
- Research Org:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Sponsoring Org:
- USDOE
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE
- OSTI Identifier:
- 1490646
Turnbull, Robin, Hanfland, Michael, Binns, Jack, Martinez-Canales, Miguel, Frost, Mungo, Marqués, Miriam, Howie, Ross T., and Gregoryanz, Eugene. Unusually complex phase of dense nitrogen at extreme conditions. United States: N. p.,
Web. doi:10.1038/s41467-018-07074-4.
Turnbull, Robin, Hanfland, Michael, Binns, Jack, Martinez-Canales, Miguel, Frost, Mungo, Marqués, Miriam, Howie, Ross T., & Gregoryanz, Eugene. Unusually complex phase of dense nitrogen at extreme conditions. United States. doi:10.1038/s41467-018-07074-4.
Turnbull, Robin, Hanfland, Michael, Binns, Jack, Martinez-Canales, Miguel, Frost, Mungo, Marqués, Miriam, Howie, Ross T., and Gregoryanz, Eugene. 2018.
"Unusually complex phase of dense nitrogen at extreme conditions". United States.
doi:10.1038/s41467-018-07074-4. https://www.osti.gov/servlets/purl/1490646.
@article{osti_1490646,
title = {Unusually complex phase of dense nitrogen at extreme conditions},
author = {Turnbull, Robin and Hanfland, Michael and Binns, Jack and Martinez-Canales, Miguel and Frost, Mungo and Marqués, Miriam and Howie, Ross T. and Gregoryanz, Eugene},
abstractNote = {Here, nitrogen exhibits an exceptional polymorphism under extreme conditions, making it unique amongst the elemental diatomics and a valuable testing system for experiment-theory comparison. Despite attracting considerable attention, the structures of many high-pressure nitrogen phases still require unambiguous determination. Here, we report the structure of the elusive high-pressure high-temperature polymorph ι–N2 at 56 GPa and ambient temperature, determined by single crystal X-ray diffraction, and investigate its properties using ab initio simulations. We find that ι–N2 is characterised by an extraordinarily large unit cell containing 48 N2 molecules. Geometry optimisation favours the experimentally determined structure and density functional theory calculations find ι–N2 to have the lowest enthalpy of the molecular nitrogen polymorphs that exist between 30 and 60 GPa. The results demonstrate that very complex structures, similar to those previously only observed in metallic elements, can become energetically favourable in molecular systems at extreme pressures and temperatures.},
doi = {10.1038/s41467-018-07074-4},
journal = {Nature Communications},
number = 1,
volume = 9,
place = {United States},
year = {2018},
month = {11}
}
Works referenced in this record:
Generalized Gradient Approximation Made Simple
journal, October 1996
journal, October 1996
- Perdew, John P.; Burke, Kieron; Ernzerhof, Matthias
- Physical Review Letters, Vol. 77, Issue 18, p. 3865-3868
Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set
journal, October 1996
journal, October 1996
- Kresse, G.; Furthm�ller, J.
- Physical Review B, Vol. 54, Issue 16, p. 11169-11186
From ultrasoft pseudopotentials to the projector augmented-wave method
journal, January 1999
journal, January 1999
- Kresse, G.; Joubert, D.
- Physical Review B, Vol. 59, Issue 3, p. 1758-1775
Crystal structure refinement with SHELXL
journal, January 2015
journal, January 2015
- Sheldrick, George M.
- Acta Crystallographica Section C Structural Chemistry, Vol. 71, Issue 1, p. 3-8
SHELXT � Integrated space-group and crystal-structure determination
journal, January 2015
journal, January 2015
- Sheldrick, George M.
- Acta Crystallographica Section A Foundations and Advances, Vol. 71, Issue 1, p. 3-8