Research Article

Electronic structure of dense solid oxygen from insulator to metal investigated with X-ray Raman scattering

Hiroshi Fukui, Le The Anh, Masahiro Wada, Nozomu Hiraoka, Toshiaki Iitaka, Naohisa Hirao, Yuichi Akahama, and Tetsuo Irifune
PNAS October 22, 2019 116 (43) 21385-21391; first published October 9, 2019; https://doi.org/10.1073/pnas.1905771116

  1. Edited by Ho-Kwang Mao, Center for High Pressure Science and Technology Advanced Research, Shanghai, China, and approved September 17, 2019 (received for review April 5, 2019)

Article Figures & SI

Figures

  • Fig. 1.
    Fig. 1.

    Crystal structure of dense solid oxygen (epsilon phase) consisting of O8 units. The red spheres represent oxygen atoms, while the black lines represent the conventional (subscript c) and primitive unit cell (subscript p).

  • Fig. 2.
    Fig. 2.

    Oxygen K-edge XRS spectra. (A) Wide-range spectra at selected pressure conditions. (B) Close-up of Pi* at 12 and 55 GPa with best-fit Gaussians (red: with 533 to 535 eV, black: without 533 to 535 eV). The 2 Gaussians are almost identical at 12 GPa. See text about the shaded area. The size of the error bar is the square root of the counts at each point.

  • Fig. 3.
    Fig. 3.

    Pressure dependence of the Pi*, Sigma*, and continuum bands. Position and width of the (A and B) Pi*, (C and D) Sigma*, and (E and F) continuum bands. Solid and open symbols indicate those with and without the 533 to 535-eV region, respectively. See text about the lines in A, C, and E. The sizes of the error bars indicate the fitting uncertainties on each parameter.

  • Fig. 4.
    Fig. 4.

    Calculated XAS spectra of solid oxygen. (A) Calculated spectra with 0.2-eV Lorentzian broadening, shown in black, and convolutions of the black spectra with a 1.4-eV Gaussian, shown in red. See text about the signal labeled with asterisks. (B) Polarized spectra at selected pressure conditions. The red lines indicate those in the a–b plane, while the black lines indicate those parallel to the c axis.

  • Fig. 5.
    Fig. 5.

    Calculated band positions. (A) Pressure dependence of Pi* and Sigma* peak positions from Fig. 4A represented by open circles and squares, respectively. (B) Offset Pi* and Sigma* positions (lines) to compare to the experimental values (symbols). (C) Offsets for the values given in A to draw B.

  • Fig. 6.
    Fig. 6.

    DOSs for the ground state at 80 GPa with various intramolecular oxygen distances: 1.08 (red), 1.18 (blue, the optimized value in the calculation), 1.27 (black), and 1.36 Å (green).

  • Fig. 7.
    Fig. 7.

    Ground-state electronic band structures for oxygen along symmetric lines and the DOS at several pressure conditions. The highly symmetric positions are L (1/2, 0, 1/2), M (1/2, 1/2, 1/2), A (0, 0, 1/2), G (0, 0, 0), Y (1/2, 1/2, 0), and V (1/2, 0, 0) for the primitive basis. See text about the red and black dots in the DOS panels.

Data supplements

Back to top
Article Alerts
Email Article
Citation Tools
Request Permissions
Electronic structure of dense solid oxygen from insulator to metal investigated with X-ray Raman scattering
Hiroshi Fukui, Le The Anh, Masahiro Wada, Nozomu Hiraoka, Toshiaki Iitaka, Naohisa Hirao, Yuichi Akahama, Tetsuo Irifune
Proceedings of the National Academy of Sciences Oct 2019, 116 (43) 21385-21391; DOI: 10.1073/pnas.1905771116
Digg logo Reddit logo Twitter logo Facebook logo Google logo Mendeley logo
Proceedings of the National Academy of Sciences: 116 (43)
Table of Contents

Submit

Article Classifications

Jump to section

You May Also be Interested in

Similar Articles