# Fileset

[jz6c02439_si_001.docx](https://mdr.nims.go.jp/filesets/063f9917-41d0-4426-81a1-5188b2a13b61/download)

## Creator

[Atsuko Nakayama](https://orcid.org/0009-0002-0016-3750), Naoto Fujii, Koji Hirama, Kentaro Hamada, [Katsuya Shimizu](https://orcid.org/0000-0003-0560-8325), Yuki Nakamoto, [Satoshi Nakano](https://orcid.org/0000-0002-7010-9867), Saori Kawaguchi-Imada, [Yuichi Akahama](https://orcid.org/0000-0003-2736-9855), Ayako Ohmura

## Rights

[Creative Commons BY-NC-ND Attribution-NonCommercial-NoDerivs 4.0 International](https://creativecommons.org/licenses/by-nc-nd/4.0/)

## Other metadata

[A High-DensitySupercritical Fluid of H2](https://mdr.nims.go.jp/datasets/11d01077-af9e-493f-a144-49ece70a39dd)

## Fulltext

Supporting Information forA High-Density Supercritical Fluid of H2Atsuko Nakayama,1* Naoto Fujii,2 Koji Hirama,2 Kentaro Hamada,2 Katsuya Shimizu,3, 4Yuki Nakamoto,3 Satoshi Nakano,5 Saori Kawaguchi-Imada,6, 7 Yuichi Akahama,8 and Ayako Ohmura91Department of Mathematical Science and Physics, Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan2Graduate School of Arts and Science, Iwate University, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan3KYOKUGEN, Center for Science and Technology under Extreme Conditions, The University of Osaka, Machikaneyama 1-3, Toyonaka, Osaka 560-8531, Japan4Geodynamics Research Center, Ehime University, 2-5 Bunkyo-Cho, Matsuyama, Ehime 790-8577, Japan5National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan6Diffraction and Scattering Division, Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan7 Office of Institutional Advancement and Communications, Kyoto University, 1-1-1Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan 8Graduate School of Material Science, University of Hyogo, 3-2-1 Kamigohri, Hyogo 678-1297, Japan9Faculty of Science, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181, Japan The supporting information file contains: Additional analysis of the S(Q) versus Q plotsFigure S1: Results of peak fitting using Lorentzian and Gaussian functions.Table S1: Parameters of peaks 0−6 determined by peak analysis using Lorentzian and Gaussian functions.Table S2: Parameters of the main and unknown peaks determined by peak analysis using Lorentzian functions at all the pressure points measured.Additional analysis of the S(Q) versus Q plotsThe S(Q) versus Q plots derived from the XRD results of SCF H2 were fitted using Gaussian functions in addition to the Lorentzian functions (see Figure S1 for the results of peak fitting using Lorentzian and Gaussian functions). The pressure points shown in the figure (0.49, 0.56 and 1.17 GPa) correspond to the pressure points before, during and after the crossover. In each plot, small or broad peaks other than the main peak originate from the background and could not be removed by subtracting the background from that of H2. For the background peaks 0, 2, 3, 4, and 6, peak positions, FWHMs, and integrated intensities showed little variation with pressure. Although the broad peak 1 could not be identified, the line shape changed with pressure. The peaks obtained at each pressure exhibited a similar trend, regardless of the function selected. This demonstrates that this phenomenon is independent of the analytical method used. Upon applying the Gaussian functions, it was confirmed that ‘unknown peak 1’ remained, particularly at 1.17 GPa, probably due to differences in the half-width and the shape of the tails of Lorentzian functions. The peak positions (pp), full width at half maximum (FWHM), integrated intensities (II) and uncertainties (PU) for peaks 0–6 were determined at 0.49, 0.56 and 1.17 GPa, as well as the R-factor, which indicates the degree of deviation from the Lorentzian or Gaussian functions used to fit the measured data (see Table S1 for parameters of peaks 0−6 determined by peak analysis using Lorentzian and Gaussian functions). Main peak 5 shown in Figure 2 in the main text, and the unknown peak 1 were analyzed using the Lorentzian functions (see Tables S2 for parameters of the main and unknown peaks determined by peak analysis using Lorentzian functions at all the pressure points measured).(a1)                                                     (a2)           (b1)                                                    (b2)           (c1)                                                     (c2)          Figure S1. Results of peak fitting using Lorentzian and Gaussian functions: (a1) 0.49 GPa using Lorentzian; (a2) 0.49 GPa by Gaussian; (b1) 0.56 GPa by Lorentzian; (b2) 0.56 GPa by Gaussian; (c1) 1.17 GPa by Lorentzian; and (c2) 1.17 GPa by Gaussian. The main peak at each pressure is indicated by arrows.Table S1. Parameters of peaks 0−6 determined by peak analysis using Lorentzian and Gaussian functions. The listed parameters are peak position (PP), full width at half maximum (FWHM), integrated intensity (II), parameter uncertainty (PU), and the R-factor.(a1) 0.49 GPa by Lorentzian, R-factor: 0.00085382 Peak No PP and PU(Å-1) FWHM and PU(Å-1) II and PU 0 1.15139  0.000534977 0.0153533 0.0016816 0.000722999 0.0000622207 1 1.19374 0.00374852 0.974977 0.031269 0.243762 0.0168647 2 1.58577 0.00325267 0.054528 0.0121941 0.000818386 0.000170628 3 1.66168 0.00111696 0.014607 0.00343692 0.000322527 0.0000583754 4 1.73808 0.00101222 0.026089 0.00327965 0.000847464 0.0000870327 5 2.16634 0.00295713 1.63956 0.0271436 0.74247 0.023497 6 2.53569 0.000887116 0.0118467 0.00266381 0.000294856 0.000049728(a2) 0.49 GPa by Gaussian, R-factor: 0.000782154 Peak No PP and PU(Å-1) FWHM and PU(Å-1) II and PU 0 1.15127  0.000519332 0.0187019 0.0012635 0.000560923 0.0000348898 1 1.13852 0.0126702 0.874046 0.0411436 0.179569 0.0273357 2 1.5855 0.00328717 0.0534104 0.00877637 0.000429466 0.0000759502 3 1.66177 0.00106485 0.0177251 0.00261594 0.000252986 0.0000353264 4 1.73858 0.00114059 0.0339653 0.00290418 0.000625628 0.0000528878 5 2.10516 0.00509613 1.19312 0.0209325 0.307625 0.0128744 6 2.53561 0.000867736 0.014449 0.00208048 0.000227538 0.0000293687(b1) 0.56 GPa by Lorentzian, R-factor: 0.000980557 Peak No PP and PU(Å-1) FWHM and PU(Å-1) II and PU 0 1.15325  0.00059324 0.0154418 0.00196838 0.000763131 0.000080533 1 1.25531 0.0166754 1.1278 0.101733 0.384089 0.0943455 2 1.58419 0.00225111 0.0445824 0.00894428 0.00099808 0.000202625 3 1.66063 0.000898261 0.0113664 0.00280266 0.000319271 0.0000617913 4 1.7359 0.00190544 0.069946 0.00782973 0.00239887 0.000283983 5 2.23912 0.00330273 1.44908 0.0209839 0.853167 0.0293419 6 2.53447 0.00118088 0.0101171 0.00352734 0.000202755 0.0000527347(b2) 0.56 GPa by Gaussian, R-factor: 0.00106124 Peak No PP and PU(Å-1) FWHM and PU(Å-1) II and PU 0 1.15305  0.000598492 0.0179195 0.001454 0.000571947 0.000042604 1 1.29358 0.0076679 0.950076 0.0490217 0.213175 0.0261986 2 1.58367 0.00256071 0.0404305 0.0066949 0.000454055 0.0000772254 3 1.66094 0.000960297 0.0145724 0.00234736 0.000261976 0.000039524 4 1.73481 0.00165857 0.0541292 0.00441805 0.00108884 0.0000953062 5 2.2236 0.00935995 0.972908 0.0195115 0.280743 0.00895272 6 2.53437 0.00114272 0.0112526 0.00272941 0.000148809 0.0000321294(c1) 1.17 GPa by Lorentzian, R-factor: 0.00204768 Peak No PP and PU(Å-1) FWHM and PU(Å-1) II and PU 0 1.15942  0.00107148 0.0257591 0.00346167 0.0020564 0.000224826 1 1.5948 0.000863987 0.0166164 0.00268471 0.00132148 0.000167394 2 1.66216 0.00100166 0.0124374 0.00318979 0.000737917 0.000152798 3 1.73326 0.000800117 0.0208679 0.00297084 0.00201569 0.000267601 4 1.83898 0.0102608 0.282007 0.0401651 0.0129136 0.00213997 5 2.4681 0.00126355 0.832919 0.00828654 0.873783 0.0162808 6 2.53152 0.00102107 0.0169301 0.00320978 0.0011491 0.000171239(c2) 1.17 GPa by Gaussian, R-factor: 0.00206757 Peak No PP and PU(Å-1) FWHM and PU(Å-1) II and PU 0 1.15834  0.000983001 0.0237153 0.00243298 0.00117255 0.00011368 1 1.89758 0.00867076 0.449151 0.0137382 0.0403699 0.00192554 2 1.5958 0.00134978 0.0314899 0.0034669 0.00130804 0.000144309 3 1.66204 0.000998751 0.0149882 0.0024741 0.000579596 0.0000906657 4 1.7319 0.00082966 0.0236626 0.002084055 0.00138588 0.000118368 5 2.45778 0.00151971 0.602529 0.00694833 0.313489 0.00604465 6 2.53162 0.001032 0.0195899 0.00252494 0.000837597 0.000100354Table S2. Parameters of the main and unknown peaks determined by peak analysis using Lorentzian functions at all the pressure points measured.(a) Main peak 5. (Maximum uncertainty in pressure was 0.0352 GPa at a pressure of 0.41 GPa.) P(GPa) PP and PU(Å-1) FWHM and PU(Å-1) II and PU R-factor 0.28 1.94935  0.00922820 2.39999 0.107349 2.3403 0.231247 0.000690164 0.32 2.01202 0.00584458 2.16768 0.0787306 2.26621 0.174446 0.000808385 0.37 2.05693 0.00442460 2.28768 0.0744314 1.40752 0.102339 0.000444955 0.41 2.11471 0.00532282 2.08632 0.0658053 1.08579 0.077174 0.000499862 0.44 2.17246 0.00343127 2.05461 0.0367555 1.3209 0.0626903 0.000622805 0.49 2.16634 0.00295713 1.63956 0.0271436 0.74247 0.023497 0.00085382 0.50 2.24757 0.01047690 1.95177 0.0683173 1.28498 0.125281 0.000677089 0.54 2.28011 0.00875512 1.66327 0.0533997 0.550003 0.0464143 0.000451801 0.55 2.30966 0.01217590 1.91289 0.0692744 0.825539 0.0869233 0.000430184 0.56 2.23912 0.00330273 1.44908 0.0209839 0.853167 0.0293419 0.000980557 0.60 2.25233 0.00351320 1.12059 0.0298538 0.816443 0.0498639 0.00103771 0.63 2.29477 0.00328899 1.07178 0.0190868 0.685154 0.0237716 0.000945679 0.67 2.28561 0.00349628 1.19949 0.0234859 1.40842 0.0651207 0.00150004 0.73 2.32583 0.00275687 1.05401 0.0188684 1.15446 0.0393973 0.00191493 0.77 2.34388 0.00203255 0.972059 0.0156772 0.755889 0.0245828 0.00148365 0.86 2.37908 0.00172899 0.964695 0.0138337 0.983541 0.0271178 0.0018246 0.98 2.40826 0.00151261 0.912965 0.0113034 0.660591 0.0197052 0.00119234 1.08 2.44152 0.00143816 0.891790 0.0102377 0.803072 0.0175699 0.00175935 1.17 2.46810 0.00126355 0.832919 0.00828654 0.873783 0.0162808 0.00204768(b) Unknown peak 1. P(GPa) PP and PU(Å-1) FWHM and PU(Å-1) II and PU 0.28 1.26088  0.00503991 0.662873 0.0335795 0.161387 0.0211317 0.32 1.21   0.00923396 0.805901 0.0471481 0.319521 0.053045 0.37 1.23746 0.00411502 0.627837 0.0215724 0.115648  0.00983125 0.41 1.24617 0.00612221 0.686215 0.0340029 0.101459 0.0122397 0.44 1.26252 0.0052999 0.636079 0.0232672 0.0954395 0.00726548 0.49 1.19374 0.00374852 0.974977 0.031269 0.243762 0.0168647 0.50 1.18145 0.0231514 0.96095 0.0993975 0.22406 0.0722495 0.54 1.24011 0.0102078 0.709205 0.0524735 0.0648914 0.0119504 0.55 1.19695 0.016784 0.841811 0.0744497 0.1031 0.0266295 0.56 1.25531 0.0166754 1.1278 0.101733 0.384089 0.0943455 0.60 1.30737 0.0144372 0.833306 0.0899764 0.279223 0.0796913 0.63 1.56971 0.000908573 0.0166046 0.00330404 0.000743273 0.000140829 0.67 1.31928 0.00742942 0.757443 0.061705 0.391396 0.0766718 0.73 1.32191 0.00470128 0.574506 0.0382471 0.155851 0.0190485 0.77 1.34167 0.00896849 0.562586 0.0729606 0.0786616 0.0220334 0.86 1.34798  0.00795642 0.428086 0.0581694 0.0429084 0.0113816 0.98 1.15571 0.000540498 0.029907 0.00281571 0.00296318 0.000357081 1.08 1.21257 0.00262172 0.022916 0.00911839 0.000733282 0.000266145 1.17 1.5948 0.000863987 0.0166164 0.00268471 0.00132148 0.000167394image5.pngimage6.pngimage10.pngimage20.pngimage30.pngimage40.pngimage50.pngimage60.pngimage1.pngimage2.pngimage3.pngimage4.png