TY - JOUR
T1 - Formation and Stability of Dense Methane-Hydrogen Compounds
AU - Ranieri, Umbertoluca
AU - Conway, Lewis J.
AU - Donnelly, Mary-Ellen
AU - Hu, Huixin
AU - Wang, Mengnan
AU - Dalladay-Simpson, Philip
AU - Pena-Alvarez, Miriam
AU - Gregoryanz, Eugene
AU - Hermann, Andreas
AU - Howie, Ross T.
N1 - Funding Information:
Parts of this research were carried out at P02.2 at DESY, a member of the Helmholtz Association (HGF), and we thank H.-P. Liermann and K. Glazyrin for assistance. We also acknowledge the European Synchrotron Radiation Facility for provision of synchrotron radiation facilities at the ID15B beam line and assistance from M. Hanfland and D. Comboni. R. T. H. acknowledges that the project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Grant Agreement No. 948895 “MetElOne”). M. P.-A. acknowledges the support of the UKRI Future leaders fellowship Mrc-Mr/T043733/1. L. J. C. was supported by the Engineering and Physical Sciences Research Council through the Condensed Matter Center for Doctoral Training (EP/L015110/1). Computational resources provided by the United Kingdom’s National Supercomputer Service through the United Kingdom Car-Parrinello consortium (EP/P022561/1) and Project ID No. d56 “Planetary Interiors” and by the United Kingdom Materials and Molecular Modelling Hub (EP/P020194) are gratefully acknowledged. The authors thank J. Binns and F. A. Gorelli for useful discussions.
Publisher Copyright:
© 2022 American Physical Society.
PY - 2022/5/27
Y1 - 2022/5/27
N2 - Through a series of x-ray diffraction, optical spectroscopy diamond anvil cell experiments, combined with density functional theory calculations, we explore the dense CH4−H2 system. We find that pressures as low as 4.8 GPa can stabilize CH4(H2)2 and (CH4)2H2, with the latter exhibiting extreme hardening of the intramolecular vibrational mode of H2 units within the structure. On further compression, a unique structural composition, (CH4)3(H2)25, emerges. This novel structure holds a vast amount of molecular hydrogen and represents the first compound to surpass 50 wt % H2. These compounds, stabilized by nuclear quantum effects, persist over a broad pressure regime, exceeding 160 GPa.
AB - Through a series of x-ray diffraction, optical spectroscopy diamond anvil cell experiments, combined with density functional theory calculations, we explore the dense CH4−H2 system. We find that pressures as low as 4.8 GPa can stabilize CH4(H2)2 and (CH4)2H2, with the latter exhibiting extreme hardening of the intramolecular vibrational mode of H2 units within the structure. On further compression, a unique structural composition, (CH4)3(H2)25, emerges. This novel structure holds a vast amount of molecular hydrogen and represents the first compound to surpass 50 wt % H2. These compounds, stabilized by nuclear quantum effects, persist over a broad pressure regime, exceeding 160 GPa.
U2 - 10.1103/PhysRevLett.128.215702
DO - 10.1103/PhysRevLett.128.215702
M3 - Article
SN - 0031-9007
VL - 128
SP - 1
EP - 6
JO - Physical Review Letters
JF - Physical Review Letters
IS - 21
M1 - 215702
ER -