Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

Chemistry under high pressure

Nature Reviews Chemistry volume 4, pages 508–527 (2020)Cite this article

Subjects

Abstract

Thanks to the development of experimental high-pressure techniques and methods for crystal-structure prediction based on quantum mechanics, in the past decade, numerous new compounds, mostly binary, with atypical compositions have been predicted, and some have been synthesized. Differing from conventional solid-state materials, many of these new compounds are comprised of various homonuclear chemical species, such as dimers, trimers, pentagonal and heptagonal rings, polymeric chains, atomic layers and 3D networks. Strikingly, it has been shown that pressure can alter the chemistry of an element by activating its (semi)core electrons, unoccupied orbitals and even the non-atom-centred quantum orbitals located on the interstitial sites, leading to many new surprising phenomena. This Review provides a summary of atypical compounds that result from the effects of high pressure on either the chemical bonds or the local orbitals. We describe various unusual chemical species and motifs, show how the chemical properties of the elements are altered under pressure and illustrate how compound formation is favoured even in situations in which chemical bonds are not formed. An extraordinary new picture of chemistry emerges as we piece together these unexpected high-pressure phenomena. In marked contrast to the previously held beliefs regarding the behaviour of solids under pressure, we are learning that the quantum-mechanical features of electrons, such as those that lead to the formation of directional bonds, inhomogeneous distributions of electrons and atoms, as well as variations in symmetry, might be magnified under pressure. We discuss the influence of these phenomena on future studies that will probe chemistry at higher pressures and explore more complex chemical compositions than those that have been studied to date.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Selected homonuclear species present in atypical high-pressure compounds.
Fig. 2: Predicted structural evolution of compounds formed via the involvement of non-valence electrons and orbitals under pressure.
Fig. 3: Chemistry of core electrons.
Fig. 4: Chemistry of non-valence orbitals.
Fig. 5: Quasiatoms and their chemistry.
Fig. 6: Chemistry without chemical bonds and the mechanism of He insertion in ionic compounds.

Similar content being viewed by others

References

  1. McMillan, P. F. Pressing on: the legacy of Percy W. Bridgman. Nat. Mater. 4, 715–718 (2005).

    PubMed  CAS  Google Scholar 

  2. Hemley, R. J. Percy W. Bridgman’s second century. High Press. Res. 30, 581–619 (2010).

    CAS  Google Scholar 

  3. Dubrovinsky, L., Dubrovinskaia, N., Prakapenka, V. B. & Abakumov, A. M. Implementation of micro-ball nanodiamond anvils for high-pressure studies above 6 Mbar. Nat. Commun. 3, 1163 (2012).

    PubMed  Google Scholar 

  4. Dubrovinsky, L. et al. The most incompressible metal osmium at static pressures above 750 gigapascals. Nature 525, 226–229 (2015).

    PubMed  CAS  Google Scholar 

  5. Dubrovinskaia, N. et al. Terapascal static pressure generation with ultrahigh yield strength nanodiamond. Sci. Adv. 2, e1600341 (2016).

    PubMed  PubMed Central  Google Scholar 

  6. Zhang, L., Wang, Y., Lv, J. & Ma, Y. Materials discovery at high pressures. Nat. Rev. Mater. 2, 17005 (2017).

    CAS  Google Scholar 

  7. Brazhkin, V. V. High-pressure synthesized materials: Treasures and hints. High Press. Res. 27, 333–351 (2007).

    CAS  Google Scholar 

  8. Shen, G. & Mao, H. K. High-pressure studies with x-rays using diamond anvil cells. Rep. Prog. Phys. 80, 016101 (2017).

    PubMed  Google Scholar 

  9. Badding, J. V. High-pressure synthesis, characterization, and tuning of solid state materials. Annu. Rev. Mater. Sci. 28, 631–658 (1998).

    CAS  Google Scholar 

  10. Mao, H. K., Chen, X. J., Ding, Y., Li, B. & Wang, L. Solids, liquids, and gases under high pressure. Rev. Mod. Phys. 90, 015007 (2018).

    CAS  Google Scholar 

  11. Pickard, C. J. & Needs, R. J. High-pressure phases of silane. Phys. Rev. Lett. 97, 045504 (2006).

    PubMed  Google Scholar 

  12. Pickard, C. J. & Needs, R. J. Structures at high pressure from random searching. Phys. Status Solidi B 246, 536–540 (2009).

    CAS  Google Scholar 

  13. Pickard, C. J. & Needs, R. J. Ab initio random structure searching. J. Phys. Condens. Matter 23, 053201 (2011).

    PubMed  Google Scholar 

  14. Needs, R. J. & Pickard, C. J. Perspective: role of structure prediction in materials discovery and design. APL. Mater. 4, 053210 (2016).

    Google Scholar 

  15. Oganov, A. R. & Glass, C. W. Crystal structure prediction using ab initio evolutionary techniques: Principles and applications. J. Chem. Phys. 124, 244704 (2006).

    PubMed  Google Scholar 

  16. Glass, C. W., Oganov, A. R. & Hansen, N. USPEX - Evolutionary crystal structure prediction. Comput. Phys. Commun. 175, 713–720 (2006).

    CAS  Google Scholar 

  17. Oganov, A. R., Lyakhov, A. O. & Valle, M. How evolutionary crystal structure prediction works and why. Acc. Chem. Res. 44, 227–237 (2011).

    PubMed  CAS  Google Scholar 

  18. Lyakhov, A. O., Oganov, A. R., Stokes, H. T. & Zhu, Q. New developments in evolutionary structure prediction algorithm USPEX. Comput. Phys. Commun. 184, 1172–1182 (2013).

    CAS  Google Scholar 

  19. Zhu, Q., Oganov, A. R. & Zhou, X. F. Crystal structure prediction and its application in earth and materials sciences. Top. Curr. Chem. 345, 223–256 (2014).

    PubMed  CAS  Google Scholar 

  20. Zurek, E. & Grochala, W. Predicting crystal structures and properties of matter under extreme conditions via quantum mechanics: the pressure is on. Phys. Chem. Chem. Phys. 17, 2917–2934 (2015).

    PubMed  CAS  Google Scholar 

  21. Zurek, E. Discovering new materials via a priori crystal structure prediction. Rev. Comp. Chem. 29, 274–326 (2016).

    CAS  Google Scholar 

  22. Wang, Y., Lv, J., Zhu, L. & Ma, Y. Crystal structure prediction via particle-swarm optimization. Phys. Rev. B 82, 094116 (2010).

    Google Scholar 

  23. Wang, Y., Lv, J., Zhu, L. & Ma, Y. CALYPSO: a method for crystal structure prediction. Comput. Phys. Commun. 183, 2063–2070 (2012).

    CAS  Google Scholar 

  24. Wang, H. et al. CALYPSO structure prediction method and its wide application. Comput. Mater. Sci. 112, 406–415 (2016).

    CAS  Google Scholar 

  25. Su, C. et al. Construction of crystal structure prototype database: Methods and applications. J. Phys. Condens. Matter 29, 165901 (2017).

    PubMed  Google Scholar 

  26. McMahon, M. I. & Nelmes, R. J. High-pressure structures and phase transformations in elemental metals. Chem. Soc. Rev. 35, 943–963 (2006).

    PubMed  CAS  Google Scholar 

  27. Hemley, R. J., Jephcoat, A. P., Mao, H. K., Ming, L. C. & Manghnani, M. H. Pressure-induced amorphization of crystalline silica. Nature 334, 52–54 (1988).

    CAS  Google Scholar 

  28. Itie, J. P. et al. Pressure-induced coordination changes in crystalline and vitreous GeO2. Phys. Rev. Lett. 63, 398–401 (1989).

    PubMed  CAS  Google Scholar 

  29. Nunez-Regueiro, M., Marques, L., Hodeau, J. L., Bethoux, O. & Perroux, M. Polymerized fullerite structures. Phys. Rev. Lett. 74, 278–281 (1995).

    PubMed  CAS  Google Scholar 

  30. Blank, V. D. et al. High-pressure polymerized phases of C60. Carbon 36, 319–343 (1998).

    CAS  Google Scholar 

  31. Iota, V. Quartzlike carbon dioxide: An optically nonlinear extended solid at high pressures and temperatures. Science 283, 1510–1513 (1999).

    PubMed  CAS  Google Scholar 

  32. Yong, X. et al. Crystal structures and dynamical properties of dense CO2. Proc. Natl Acad. Sci. USA 113, 11110–11115 (2016).

    PubMed  PubMed Central  CAS  Google Scholar 

  33. Yoo, C. S. et al. Crystal structure of carbon dioxide at high pressure: “Superhard” polymeric carbon dioxide. Phys. Rev. Lett. 83, 5527–5530 (1999).

    CAS  Google Scholar 

  34. Lin, J. F. & Tsuchiya, T. Spin transition of iron in the Earth’s lower mantle. Phys. Earth Planet. Inter. 170, 248–259 (2008).

    CAS  Google Scholar 

  35. Lyubutin, I. S. et al. Spin transition of Fe2+ in ringwoodite (Mg,Fe)2SiO4 at high pressures. Am. Mineral. 98, 1803–1810 (2013).

    CAS  Google Scholar 

  36. Lin, J.-F. et al. Pressure-induced electronic spin transition of iron in magnesiowustite-(Mg,Fe)O. Phys. Rev. B 73, 113107 (2006).

    Google Scholar 

  37. Drickamer, H. G. & Frank, C. W. Electronic Transitions and the High Pressure Chemistry and Physics of Solids (Springer, 2013).

  38. Buzea, C. & Robbie, K. Assembling the puzzle of superconducting elements: a review. Supercond. Sci. Technol. 18, R1–R8 (2005).

    CAS  Google Scholar 

  39. Schilling, J. S. Superconductivity in the alkali metals. High Press. Res. 26, 145–163 (2006).

    CAS  Google Scholar 

  40. Sakata, M., Nakamoto, Y., Shimizu, K., Matsuoka, T. & Ohishi, Y. Superconducting state of Ca-VII below a critical temperature of 29 K at a pressure of 216 GPa. Phys. Rev. B 83, 220512 (2011).

    Google Scholar 

  41. Matsuoka, T. et al. Pressure-induced superconductivity in CaLi2. Phys. Rev. Lett. 100, 197003 (2008).

    PubMed  CAS  Google Scholar 

  42. Chen, X. J. et al. Superconducting behavior in compressed solid SiH4 with a layered structure. Phys. Rev. Lett. 101, 077002 (2008).

    PubMed  Google Scholar 

  43. Li, Y., Hao, J., Liu, H., Li, Y. & Ma, Y. The metallization and superconductivity of dense hydrogen sulfide. J. Chem. Phys. 140, 174712 (2014).

    PubMed  Google Scholar 

  44. Duan, D. et al. Pressure-induced metallization of dense (H2S)2H2 with high-Tc superconductivity. Sci. Rep. 4, 6968 (2014).

    PubMed  PubMed Central  CAS  Google Scholar 

  45. Drozdov, A. P., Eremets, M. I., Troyan, I. A., Ksenofontov, V. & Shylin, S. I. Conventional superconductivity at 203 kelvin at high pressures in the sulfur hydride system. Nature 525, 73–76 (2015). The first synthesis of a superconducting hydride that broke the 30-year Tc record of cuprates, revealing the potential of compounds with atypical compositions at achieving unusual properties.

    PubMed  CAS  Google Scholar 

  46. Errea, I. et al. High-pressure hydrogen sulfide from first principles: a strongly anharmonic phonon-mediated superconductor. Phys. Rev. Lett. 114, 157004 (2015).

    PubMed  Google Scholar 

  47. Akashi, R., Sano, W., Arita, R. & Tsuneyuki, S. Possible ‘Magneli’ phases and self-alloying in the superconducting sulfur hydride. Phys. Rev. Lett. 117, 075503 (2016).

    PubMed  Google Scholar 

  48. Li, X., Liu, H. & Peng, F. Crystal structures and superconductivity of technetium hydrides under pressure. Phys. Chem. Chem. Phys. 18, 28791–28796 (2016).

    PubMed  CAS  Google Scholar 

  49. Errea, I. et al. Quantum hydrogen-bond symmetrization in the superconducting hydrogen sulfide system. Nature 532, 81–84 (2016).

    PubMed  CAS  Google Scholar 

  50. Zhang, W. W. et al. Unexpected stable stoichiometries of sodium chlorides. Science 342, 1502–1505 (2013). A good example showing, by using both DFT calculations and diamond anvil cell experiments, that common compounds such as NaCl can assume very different (atypical) compositions under high pressure.

    PubMed  CAS  Google Scholar 

  51. Peng, F., Yao, Y., Liu, H. & Ma, Y. Crystalline LiN5 predicted from first-principles as a possible high-energy material. J. Phys. Chem. Lett. 6, 2363–2366 (2015).

    PubMed  CAS  Google Scholar 

  52. Shen, Y. et al. Novel lithium-nitrogen compounds at ambient and high pressures. Sci. Rep. 5, 14204 (2015).

    PubMed  PubMed Central  Google Scholar 

  53. Hemley, R. J., Ahart, M., Liu, H. & Somayazulu, M. in Proceedings of the International Symposium - Superconductivity and Pressure: A Fruitful Relationship on the Road to Room Temperature Superconductivity (ed. Alario-Franco, M. A.) 199–213 (Fundación Ramón Areces, 2019).

  54. Liu, H., Naumov, I. I., Hoffmann, R., Ashcroft, N. W. & Hemley, R. J. Potential high-Tc superconducting lanthanum and yttrium hydrides at high pressure. Proc. Natl Acad. Sci. USA 114, 6990 (2017).

    PubMed  PubMed Central  CAS  Google Scholar 

  55. Somayazulu, M. et al. Evidence for superconductivity above 260 K in lanthanum superhydride at megabar pressures. Phys. Rev. Lett. 122, 027001 (2019).

    PubMed  CAS  Google Scholar 

  56. Peng, F. et al. Hydrogen clathrate structures in rare earth hydrides at high pressures: Possible route to room-temperature superconductivity. Phys. Rev. Lett. 119, 107001 (2017).

    PubMed  Google Scholar 

  57. Drozdov, A. P. et al. Superconductivity at 250 K in lanthanum hydride under high pressures. Nature 569, 528–531 (2019).

    PubMed  CAS  Google Scholar 

  58. Geballe, Z. M. et al. Synthesis and stability of lanthanum superhydrides. Angew. Chem. Int. Ed. 57, 688–692 (2018).

    CAS  Google Scholar 

  59. Zhu, L., Liu, H., Pickard, C. J., Zou, G. & Ma, Y. Reactions of xenon with iron and nickel are predicted in the Earth’s inner core. Nat. Chem. 6, 644–648 (2014). DFT calculations and crystal structure prediction searches reveal that Xe can become reactive with Fe under pressure, and show how the modification of the properties of these elements can provide answers to geochemistry puzzles.

    PubMed  CAS  Google Scholar 

  60. Miao, M. S. Cesium in high oxidation states and as a p-block element. Nat. Chem. 5, 846–852 (2013). Being the first example of core electron reactivity, this work uses DFT calculations to show how elements can change their chemical identity under high pressure.

    PubMed  CAS  Google Scholar 

  61. Dong, X. et al. A stable compound of helium and sodium at high pressure. Nat. Chem. 9, 440–445 (2017). DFT calculations and diamond anvil cell experiments are used to demonstrate the first example of a stable solid He containing compound.

    PubMed  CAS  Google Scholar 

  62. Pauling, L. The Nature of the Chemical Bond and the Structure of Molecules and Crystals: An Introduction to Modern Structural Chemistry (Cornell Univ. Press, 1960).

  63. Prewitt, C. T. & Downs, R. T. in Ultrahigh Pressure Mineralogy (ed. Hemley, R. J.) 283–318 (De Gruyter, 1998).

  64. Grochala, W., Hoffmann, R., Feng, J. & Ashcroft, N. W. The chemical imagination at work in very tight places. Angew. Chem. Int. Ed. 46, 3620–3642 (2007).

    CAS  Google Scholar 

  65. Ashcroft, N. W. & Mermin, N. D. Solid State Physics (Holt, Rinehart and Winston, 1976).

  66. Hanfland, M., Syassen, K., Christensen, N. E. & Novikov, D. L. New high-pressure phases of lithium. Nature 408, 174–178 (2000).

    PubMed  CAS  Google Scholar 

  67. Ma, Y. et al. Transparent dense sodium. Nature 458, 182–185 (2009). One of the first studies demonstrating that simple metals like Na can become high-pressure electrides, performed using both DFT calculations and diamond anvil cell experiments.

    PubMed  CAS  Google Scholar 

  68. Miao, M.-S. & Hoffmann, R. High pressure electrides: a predictive chemical and physical theory. Acc. Chem. Res. 47, 1311–1317 (2014). This theoretical study illustrates that the occupation of local orbitals at interstitial sites (quasi-atoms) is the mechanism that leads to the formation of high-pressure electrides, providing a route to understanding many related phenomena.

    PubMed  CAS  Google Scholar 

  69. Oganov, A. R., Pickard, C. J., Zhu, Q. & Needs, R. J. Structure prediction drives materials discovery. Nat. Rev. Mater. 4, 331–348 (2019).

    Google Scholar 

  70. Botana, J. et al. Mercury under pressure acts as a transition metal: calculated from first principles. Angew. Chem. Int. Ed. 54, 9280–9283 (2015).

    CAS  Google Scholar 

  71. Botana, J. & Miao, M. S. Pressure-stabilized lithium caesides with caesium anions beyond the −1 state. Nat. Commun. 5, 4861 (2014). DFT calculations demonstrate how the non-valence orbitals are involved in chemical bonds, and show how these affect structures and properties of the compounds under pressure.

    PubMed  CAS  Google Scholar 

  72. Housecroft, C. E. & Sharpe, A. G. Inorganic Chemistry (Pearson Prentice Hall, 2012).

  73. Cotton, F. A., Wilkinson, G., Murillo, C. A. & Bochmann, M. Advanced Inorganic Chemistry 6th edn (Wiley, 1999).

  74. Janka, O. & Kauzlarich, S. M. in Encyclopedia of Inorganic and Bioinorganic Chemistry (Wiley, 2014).

  75. Scharfe, S., Kraus, F., Stegmaier, S., Schier, A. & Fässler, T. F. Zintl ions, cage compounds, and intermetalloid clusters of group 14 and group 15 elements. Angew. Chem. Int. Ed. 50, 3630–3670 (2011).

    CAS  Google Scholar 

  76. Peng, F., Miao, M., Wang, H., Li, Q. & Ma, Y. Predicted lithium-boron compounds under high pressure. J. Am. Chem. Soc. 134, 18599–18605 (2012).

    PubMed  CAS  Google Scholar 

  77. Hermann, A. et al. LiB and its boron-deficient variants under pressure. Phys. Rev. B 86, 144110 (2012).

    Google Scholar 

  78. Ashcroft, N. W. Hydrogen dominant metallic alloys: High temperature superconductors? Phys. Rev. Lett. 92, 187002 (2004). This pioneering study proposes that chemical pre-compression may be a way to metallize H-rich compounds at experimentally accessible pressures.

    PubMed  CAS  Google Scholar 

  79. Zurek, E, Hoffmann, R., Ashcroft, N. W., Oganov A. R., & Lyakhov A. O. A little bit of lithium does a lot for hydrogen. Proc. Natl. Acad. Sci. USA 106, 17640 (2009). The first DFT study on hydrogen metallization in atypical metal hydrides with hydrogen rich composition, actualizing the pre-compression strategy proposed in Ref. 78.

    PubMed  PubMed Central  CAS  Google Scholar 

  80. Struzhkin, V. V. et al. Synthesis of sodium polyhydrides at high pressures. Nat. Commun. 7, 12267 (2016).

    PubMed  PubMed Central  CAS  Google Scholar 

  81. Pépin, C., Loubeyre, P., Occelli, F. & Dumas, P. Synthesis of lithium polyhydrides above 130 GPa at 300 K. Proc. Natl Acad. Sci. USA 112, 7673–7676 (2015).

    PubMed  PubMed Central  Google Scholar 

  82. Mishra, A. K. et al. New calcium hydrides with mixed atomic and molecular hydrogen. J. Phys. Chem. C 122, 19370–19378 (2018).

    CAS  Google Scholar 

  83. Hooper, J. & Zurek, E. Rubidium polyhydrides under pressure: emergence of the linear H3− species. Chemistry 18, 5013–5021 (2012).

    PubMed  CAS  Google Scholar 

  84. Shamp, A., Hooper, J. & Zurek, E. Compressed cesium polyhydrides: Cs+ sublattices and H3− three-connected nets. Inorg. Chem. 51, 9333–9342 (2012).

    PubMed  CAS  Google Scholar 

  85. Wang, H., Li, X., Gao, G., Li, Y. & Ma, Y. Hydrogen-rich superconductors at high pressures. Wiley Interdiscip. Rev. Comput. Mol. Sci. 8, e1330 (2018).

    Google Scholar 

  86. Wang, Z., Wang, H., Tse, J. S., Iitaka, T. & Ma, Y. Stabilization of H3+ in the high pressure crystalline structure of HnCl (n = 2–7). Chem. Sci. 6, 522–526 (2014).

    PubMed  PubMed Central  Google Scholar 

  87. Hooper, J., Terpstra, T., Shamp, A. & Zurek, E. Composition and constitution of compressed strontium polyhydrides. J. Phys. Chem. C 118, 6433–6447 (2014).

    CAS  Google Scholar 

  88. Wang, Y., Wang, H., Tse, J. S., Iitaka, T. & Ma, Y. Structural morphologies of high-pressure polymorphs of strontium hydrides. Phys. Chem. Chem. Phys. 17, 19379–19385 (2015).

    PubMed  CAS  Google Scholar 

  89. Wang, H., Tse, J. S., Tanaka, K., Iitaka, T. & Ma, Y. Superconductive sodalite-like clathrate calcium hydride at high pressures. Proc. Natl Acad. Sci. USA 109, 6463 (2012). The first DFT-based computational study predicting that metals can form superhydrides with sodalite H covalent lattices, heralding the recent remarkable discovery of superconducting metal superhydrides.

    PubMed  CAS  PubMed Central  Google Scholar 

  90. Shamp, A. & Zurek, E. Superconductivity in hydrides doped with main group elements under pressure. Nov. Supercond. Mater. 3, 14–22 (2017).

    Google Scholar 

  91. Martinez-Canales, M. et al. Novel structures and superconductivity of silane under pressure. Phys. Rev. Lett. 102, 087005 (2009).

    PubMed  Google Scholar 

  92. Cui, W. et al. Hydrogen segregation and its roles in structural stability and metallization: silane under pressure. Sci. Rep. 5, 13039 (2015).

    PubMed  PubMed Central  CAS  Google Scholar 

  93. Li, Y. et al. Superconductivity at approximately 100 K in dense SiH4(H2)2 predicted by first principles. Proc. Natl Acad. Sci. USA 107, 15708–15711 (2010).

    PubMed  CAS  PubMed Central  Google Scholar 

  94. Mahdi Davari Esfahani, M. et al. Superconductivity of novel tin hydrides (SnnHm) under pressure. Sci. Rep. 6, 22873 (2016).

    PubMed  PubMed Central  CAS  Google Scholar 

  95. Gao, G. et al. Superconducting high pressure phase of germane. Phys. Rev. Lett. 101, 107002 (2008).

    PubMed  Google Scholar 

  96. Yuan, Y. et al. Stoichiometric evolutions of PH3 under high pressure: Implication for high-Tc superconducting hydrides. Natl Sci. Rev. 6, 524–531 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  97. Flores-Livas, J. A., Sanna, A. & Gross, E. K. U. High temperature superconductivity in sulfur and selenium hydrides at high pressure. Eur. Phys. J. B 89, 63 (2016).

    Google Scholar 

  98. Flores-Livas, J. A. et al. Superconductivity in metastable phases of phosphorus-hydride compounds under high pressure. Phys. Rev. B 93, 020508 (2016).

    Google Scholar 

  99. Errea, I. et al. Quantum crystal structure in the 250-kelvin superconducting lanthanum hydride. Nature 578, 66–69 (2020).

    PubMed  CAS  Google Scholar 

  100. Zurek, E. & Bi, T. High-temperature superconductivity in alkaline and rare earth polyhydrides at high pressure: A theoretical perspective. J. Chem. Phys. 150, 050901 (2019).

    PubMed  Google Scholar 

  101. Heil, C., di Cataldo, S., Bachelet, G. B. & Boeri, L. Superconductivity in sodalite-like yttrium hydride clathrates. Phys. Rev. B 99, 220502 (2019).

    CAS  Google Scholar 

  102. Zurek, E. Viewpoint: Pushing towards room-temperature superconductivity. Physics 12, 1 (2019).

    Google Scholar 

  103. Flores-Livas, J. A. et al. A perspective on conventional high-temperature superconductors at high pressure: Methods and materials. Phys. Rep. 856, 1–78 (2020).

    CAS  Google Scholar 

  104. Etourneau, J. & Hagenmuller, P. Structure and physical features of the rare-earth borides. Philos. Mag. B 52, 589–610 (1985).

    CAS  Google Scholar 

  105. Harran, I., Chen, Y., Wang, H. & Ni, Y. Pressure induced evolution of structures and properties of iron tetraboride. CrystEngComm 20, 3928–3935 (2018).

    CAS  Google Scholar 

  106. Zhang, X. et al. First-principles structural design of superhard material of ZrB4. Phys. Chem. Chem. Phys. 15, 20894–20899 (2013).

    PubMed  CAS  Google Scholar 

  107. Li, X., Tao, Y. & Peng, F. Pressure and temperature induced phase transition in WB4: a first principles study. J. Alloys Compd. 687, 579–585 (2016).

    CAS  Google Scholar 

  108. Li, X. & Peng, F. Predicted superhard phases of Zr–B compounds under pressure. Phys. Chem. Chem. Phys. 12, 15609–15614 (2019).

    Google Scholar 

  109. Zhang, G., Bai, T., Zhao, Y. & Hu, Y. A new superhard phase and physical properties of ZrB3 from first-principles calculations. Materials 9, 703 (2016).

    PubMed Central  Google Scholar 

  110. Chu, B. et al. Structural, mechanical, and electronic properties of Rh2B and RhB2: First-principles calculations. Sci. Rep. 5, 10500 (2015).

    PubMed  PubMed Central  Google Scholar 

  111. Wang, Q. et al. Novel high-pressure phase of RhB: First-principles calculations. J. Phys. Chem. C 115, 19910–19915 (2011).

    CAS  Google Scholar 

  112. Nagamatsu, J., Nakagawa, N., Muranaka, T., Zenitani, Y. & Akimitsu, J. Superconductivity at 39 K in magnesium diboride. Nature 410, 63–64 (2001).

    PubMed  CAS  Google Scholar 

  113. Kolmogorov, A. N. et al. New superconducting and semiconducting Fe-B compounds predicted with an ab initio evolutionary search. Phys. Rev. Lett. 105, 217003 (2010).

    PubMed  CAS  Google Scholar 

  114. Gou, H. et al. Discovery of a superhard iron tetraboride superconductor. Phys. Rev. Lett. 111, 157002 (2013).

    PubMed  Google Scholar 

  115. Kolmogorov, A. N. & Curtarolo, S. Theoretical study of metal borides stability. Phys. Rev. B 74, 224507 (2006).

    Google Scholar 

  116. Kolmogorov, A. N. & Curtarolo, S. Prediction of different crystal structure phases in metal borides: A lithium monoboride analog to MgB2. Phys. Rev. B 73, 180501 (2006).

    Google Scholar 

  117. Kolmogorov, A. N., Calandra, M. & Curtarolo, S. Thermodynamic stabilities of ternary metal borides: An ab initio guide for synthesizing layered superconductors. Phys. Rev. B 78, 094520 (2008).

    Google Scholar 

  118. Hermann, A., McSorley, A., Ashcroft, N. W. & Hoffmann, R. From Wade–Mingos to Zintl–Klemm at 100 GPa: binary compounds of boron and lithium. J. Am. Chem. Soc. 134, 18606–18618 (2012).

    PubMed  CAS  Google Scholar 

  119. Kolmogorov, A. N., Hajinazar, S., Angyal, C., Kuznetsov, V. L. & Jephcoat, A. P. Synthesis of a predicted layered LiB via cold compression. Phys. Rev. B 92, 144110 (2015).

    Google Scholar 

  120. Wang, H., LeBlanc, K. A., Gao, B. & Yao, Y. Thermodynamic ground state of MgB6 predicted from first principles structure search methods. J. Chem. Phys. 140, 044710 (2014).

    PubMed  Google Scholar 

  121. Benson, D. et al. Lithium and calcium carbides with polymeric carbon structures. Inorg. Chem. 52, 6402–6406 (2013).

    PubMed  CAS  Google Scholar 

  122. Li, Y. L. et al. Pressure-induced superconductivity in CaC2. Proc. Natl Acad. Sci. USA 110, 9289–9294 (2013).

    PubMed  CAS  PubMed Central  Google Scholar 

  123. Zhong, X. et al. Pressure stabilization of long-missing bare C6 hexagonal rings in binary sesquicarbides. Chem. Sci. 5, 3936–3940 (2014).

    CAS  Google Scholar 

  124. Feng, C. et al. First-principle study of pressure-induced phase transitions and electronic properties of electride Y2C. Solid State Commun. 266, 34–38 (2017).

    CAS  Google Scholar 

  125. Guo, Y. et al. Pressure-induced structural transformations and polymerization in ThC2. Sci. Rep. 7, 45872 (2017).

    PubMed  PubMed Central  CAS  Google Scholar 

  126. Liu, H., Gao, G., Li, Y., Hao, J. & Tse, J. S. Crystal structures and chemical bonding of magnesium carbide at high pressure. J. Phys. Chem. C 119, 23168–23174 (2015).

    CAS  Google Scholar 

  127. Liu, H., Naumov & Hemley, R. J. Dense hydrocarbon structures at megabar pressures. J. Phys. Chem. Lett. 7, 4218–4222 (2016).

    PubMed  CAS  Google Scholar 

  128. Feng, X. et al. Carbon network evolution from dimers to sheets in superconducting ytrrium dicarbide under pressure. Commun. Chem. 1, 85 (2018).

    Google Scholar 

  129. Du, H. et al. Nonmetallization and band inversion in beryllium dicarbide at high pressure. Sci. Rep. 6, 26398 (2016).

    PubMed  PubMed Central  CAS  Google Scholar 

  130. Wang, D., Yan, Y., Zhou, D. & Liu, Y. Evolution of crystal and electronic structures of magnesium dicarbide at high pressure. Sci. Rep. 5, 17815 (2015).

    PubMed  PubMed Central  CAS  Google Scholar 

  131. Wei, Q., Zhang, Q., Yan, H. & Zhang, M. Cubic C3N: A new superhard phase of carbon-rich nitride. Materials 9, 840 (2016).

    PubMed Central  Google Scholar 

  132. Medvedev, S. A. et al. Phase stability of lithium azide at pressures up to 60 GPa. J. Phys. Condens. Matter 21, 195404 (2009).

    PubMed  CAS  Google Scholar 

  133. Crowhurst, J. C. et al. Synthesis and characterization of the nitrides of platinum and Iridium. Science 311, 1275–1278 (2006).

    PubMed  CAS  Google Scholar 

  134. Wang, X. et al. Polymerization of nitrogen in lithium azide. J. Chem. Phys. 139, 164710 (2013).

    PubMed  Google Scholar 

  135. Li, J. et al. Pressure-induced polymerization of nitrogen in potassium azides. EPL 104, 16005 (2013).

    Google Scholar 

  136. Wang, X., Li, J., Zhu, H., Chen, L. & Lin, H. Polymerization of nitrogen in cesium azide under modest pressure. J. Chem. Phys. 141, 044717 (2014).

    PubMed  Google Scholar 

  137. Bykov, M. et al. High-pressure synthesis of ultraincompressible hard rhenium nitride pernitride Re2(N2)(N)2 stable at ambient conditions. Nat. Commun. 10, 2994 (2019).

    PubMed  PubMed Central  Google Scholar 

  138. Bykov, M. et al. Fe-N system at high pressure reveals a compound featuring polymeric nitrogen chains. Nat. Commun. 9, 2756 (2018).

    PubMed  PubMed Central  CAS  Google Scholar 

  139. Laniel, D. et al. Synthesis of magnesium-nitrogen salts of polynitrogen anions. Nat. Commun. 10, 4515 (2019).

    PubMed  PubMed Central  Google Scholar 

  140. Yu, S. et al. Emergence of novel polynitrogen molecule-like species, covalent chains, and layers in magnesium–nitrogen MgxNy phases under high pressure. J. Phys. Chem. C 121, 11037–11046 (2017).

    CAS  Google Scholar 

  141. Wei, S. et al. Alkaline-earth metal (Mg) polynitrides at high pressure as possible high-energy materials. Phys. Chem. Chem. Phys. 19, 9246–9252 (2017).

    PubMed  CAS  Google Scholar 

  142. Chen, Y., Cai, X., Wang, H., Wang, H. & Wang, H. Novel triadius-like N4 specie of iron nitride compounds under high pressure. Sci. Rep. 8, 10670 (2018).

    PubMed  PubMed Central  Google Scholar 

  143. Vij, A., Pavlovich, J. G., Wilson, W. W., Vij, V. & Christe, K. O. Experimental detection of the pentaazacyclopentadienide (pentazolate) anion, cyclo-N5−. Angew. Chem. Int. Ed. 41, 3051–3054 (2002).

    CAS  Google Scholar 

  144. Steele, B. A. & Oleynik, I. I. Sodium pentazolate: a nitrogen rich high energy density material. Chem. Phys. Lett. 643, 21–26 (2016).

    CAS  Google Scholar 

  145. Peng, F., Han, Y., Liu, H. & Yao, Y. Exotic stable cesium polynitrides at high pressure. Sci. Rep. 5, 16902 (2015).

    PubMed  PubMed Central  CAS  Google Scholar 

  146. Li, J., Sun, L., Wang, X., Zhu, H. & Miao, M. Simple route to metal cyclo-N5– salt: High-pressure synthesis of CuN5. J. Phys. Chem. C 122, 22339–22344 (2018).

    CAS  Google Scholar 

  147. Laniel, D., Weck, G., Gaiffe, G., Garbarino, G. & Loubeyre, P. High-pressure synthesized lithium pentazolate compound metastable under ambient conditions. J. Phys. Chem. Lett. 9, 1600–1604 (2018). A good example of the synthesis of unusual compounds with desired properties by exploiting pressure-induced stabilization of homonuclear bonds.

    PubMed  CAS  Google Scholar 

  148. Yi, W. et al. Packing high-energy together: Binding the power of pentazolate and high-valence metals with strong bonds. Mater. Des. 193, 108820 (2020).

    CAS  Google Scholar 

  149. Weerasinghe, G. L., Pickard, C. J. & Needs, R. J. Computational searches for iron oxides at high pressures. J. Phys. Condens. Matter 27, 455501 (2015).

    PubMed  Google Scholar 

  150. Hu, Q. et al. FeO2 and FeOOH under deep lower-mantle conditions and Earth’s oxygen–hydrogen cycles. Nature 534, 241–244 (2016).

    PubMed  CAS  Google Scholar 

  151. Hu, Q. et al. Dehydrogenation of goethite in Earth’s deep lower mantle. Proc. Natl Acad. Sci. USA 114, 1498–1501 (2017).

    PubMed  PubMed Central  CAS  Google Scholar 

  152. Tang, M., Niu, Z.-W., Zhang, X.-L. & Cai, L.-C. Structural stability of FeO2 in the pressure range of lower mantle. J. Alloys Compd. 765, 271–277 (2018).

    CAS  Google Scholar 

  153. Huang, S. X., Wu, X. & Qin, S. Ultrahigh-pressure phase transitions in FeS2 and FeO2: Implications for super-Earths’ deep interior. J. Geophys. Res. Solid Earth 123, 277–284 (2018).

    CAS  Google Scholar 

  154. Schmidt, B., Schröder, B., Sonnenberg, K., Steinhauer, S. & Riedel, S. From polyhalides to polypseudohalides: Chemistry based on cyanogen bromide. Angew. Chem. Int. Ed. 58, 10340–10344 (2019).

    CAS  Google Scholar 

  155. Wei, S., Wang, J., Deng, S., Zhang, S. & Li, Q. Hypervalent iodine with linear chain at high pressure. Sci. Rep. 5, 14393 (2015).

    PubMed  PubMed Central  CAS  Google Scholar 

  156. Zhu, Q., Oganov, A. R. & Zeng, Q. Formation of stoichiometric CsFn compounds. Sci. Rep. 5, 7875 (2015).

    PubMed  PubMed Central  CAS  Google Scholar 

  157. Shamp, A., Saitta, P. & Zurek, E. Theoretical predictions of novel potassium chloride phases under pressure. Phys. Chem. Chem. Phys. 17, 12265–12272 (2015).

    PubMed  CAS  Google Scholar 

  158. Zhang, W. et al. Stability of numerous novel potassium chlorides at high pressure. Sci. Rep. 6, 26265 (2016).

    PubMed  PubMed Central  CAS  Google Scholar 

  159. Guerette, M. et al. Advanced synthesis of Na4Si24. MRS Adv. 3, 1427–1433 (2018).

    CAS  Google Scholar 

  160. Hohmann, E. Silicides and germanides of the alkali metals. Z. Anorg. Allg. Chem. 257, 113–126 (1948).

    CAS  Google Scholar 

  161. Witte, J. The behavior of alkali metals relative to semimetals XI, the crystal structure of NaSi and NaGe. Z. Anorg. Allg. Chem. 327, 260–273 (1964).

    CAS  Google Scholar 

  162. Goebel, T., Prots, Y. & Haarmann, F. Refinement of the crystal structure of tetrasodium tetrasilicide, Na4Si4. Z. Kristallogr. NCS. 223, 187–188 (2014).

    Google Scholar 

  163. Shi, J. et al. Investigation of new phases in the Ba–Si phase diagram under high pressure using ab initio structural search. Phys. Chem. Chem. Phys. 18, 8108–8114 (2016).

    PubMed  CAS  Google Scholar 

  164. Gao, G., Ashcroft, N. W., Miao, M. & Hoffmann, R. Novel Si networks in the Ca/Si phase diagram under pressure. J. Phys. Chem. C 118, 25167–25175 (2014).

    CAS  Google Scholar 

  165. Li, W. et al. Crystal structures of CsSi6 at high pressures. Comput. Mater. Sci. 150, 144–148 (2018).

    CAS  Google Scholar 

  166. McMahan, A. K. & Albers, R. C. Insulating nickel at a pressure of 34 TPa. Phys. Rev. Lett. 49, 1198–1201 (1982).

    CAS  Google Scholar 

  167. Parker, L. J., Atou, T. & Badding, J. V. Transition element-like chemistry for potassium under pressure. Science 273, 95–97 (1996). This work demonstrates experimentally how K behaves like a transition metal under pressure; a well-known example of how pressure changes the fundamental properties of elements.

    PubMed  CAS  Google Scholar 

  168. Takemura, K., Shimomura, O. & Fujihisa, H. CsVI: a new high-pressure polymorph of cesium above 72 GPa. Phys. Rev. Lett. 66, 2014–2017 (1991).

    PubMed  CAS  Google Scholar 

  169. Ahuja, R., Eriksson, O. & Johansson, B. Theoretical high-pressure studies of Cs metal. Phys. Rev. B 63, 014102 (2001).

    Google Scholar 

  170. Zhu, Q. et al. Stability of xenon oxides at high pressures. Nat. Chem. 5, 61–65 (2013).

    PubMed  Google Scholar 

  171. Dewaele, A. et al. Synthesis and stability of xenon oxides Xe2O5 and Xe3O2 under pressure. Nat. Chem. 8, 784–790 (2016).

    PubMed  CAS  Google Scholar 

  172. Brock, D. S. & Schrobilgen, G. J. Synthesis of the missing oxide of xenon, XeO2, and its implications for Earth’s missing xenon. J. Am. Chem. Soc. 133, 6265–6269 (2011).

    PubMed  CAS  Google Scholar 

  173. Dmochowski, I. Xenon out of its shell. Nat. Chem. 1, 250 (2009).

    PubMed  CAS  Google Scholar 

  174. Hermann, A. & Schwerdtfeger, P. Xenon suboxides stable under pressure. J. Phys. Chem. Lett. 5, 4336–4342 (2014).

    PubMed  CAS  Google Scholar 

  175. Feng, J., Hennig, R. G., Ashcroft, N. W. & Hoffmann, R. Emergent reduction of electronic state dimensionality in dense ordered Li-Be alloys. Nature 451, 445–448 (2008).

    PubMed  CAS  Google Scholar 

  176. Miao, M., Botana, J., Pravica, M., Sneed, D. & Park, C. Inner-shell chemistry under high pressure. Jpn. J. Appl. Phys. 56, 05FA10 (2017).

    Google Scholar 

  177. Pauling, L. The formulas of antimonic acid and the antimonates. J. Am. Chem. Soc. 55, 1895–1900 (1933).

    CAS  Google Scholar 

  178. Bartlett, N. Xenon hexafluoroplatinate(V) Xe+[PtF6]−. Proc. Chem. Soc. Lond. 6, 197–236 (1962).

    Google Scholar 

  179. Grochala, W. Atypical compounds of gases, which have been called ‘noble’. Chem. Soc. Rev. 36, 1632–1655 (2007).

    PubMed  CAS  Google Scholar 

  180. Wang, X., Andrews, L., Riedel, S. & Kaupp, M. Mercury is a transition metal: the first experimental evidence for HgF4. Angew. Chem. Int. Ed. 46, 8371–8375 (2007).

    CAS  Google Scholar 

  181. Riedel, S., Straka, M. & Kaupp, M. Validation of density functional methods for computing structures and energies of mercury (IV) complexes. Phys. Chem. Chem. Phys. 6, 1122–1127 (2004).

    CAS  Google Scholar 

  182. Riedel, S., Straka, M. & Kaupp, M. Can weakly coordinating anions stabilize mercury in its oxidation state +IV? Chemistry 11, 2743–2755 (2005).

    PubMed  CAS  Google Scholar 

  183. Moock, K. & Seppelt, K. Indications of cesium in a higher oxidation state. Angew. Chem. Int. Ed. Engl. 28, 1676–1678 (1989).

    Google Scholar 

  184. Jehoulet, C. & Bard, A. J. On the electrochemical oxidation of Cs⊕ and other alkali-metal ions in liquid sulfur dioxide and acetonitrile. Angew. Chem. Int. Ed. Engl. 30, 836–838 (1991).

    Google Scholar 

  185. Rahm, M., Cammi, R., Ashcroft, N. W. & Hoffmann, R. Squeezing all elements in the periodic table: Electron configuration and electronegativity of the atoms under compression. J. Am. Chem. Soc. 144, 10253–10271 (2019).

    Google Scholar 

  186. Tramsek, M. & Zemva, B. Synthesis, properties and chemistry of xenon(II) fluoride. Acta Chim. Slov. 53, 105–116 (2006).

    CAS  Google Scholar 

  187. Christe, K. O. et al. The pentafluoroxenate(IV) anion, XeF5−: the first example of a pentagonal planar AX5 species. J. Am. Chem. Soc. 113, 3351–3361 (1991).

    CAS  Google Scholar 

  188. Dronskowski, R. & Bloechl, P. E. Crystal orbital Hamilton populations (COHP): Energy-resolved visualization of chemical bonding in solids based on density-functional calculations. J. Phys. Chem. 97, 8617–8624 (1993).

    CAS  Google Scholar 

  189. Silvi, B. & Savin, A. Classification of chemical bonds based on topological analysis of electron localization functions. Nature 371, 683–686 (1994).

    CAS  Google Scholar 

  190. Rogachev, A. Y., Miao, M., Merino, G. & Hoffmann, R. Molecular CsF5 and CsF2+. Angew. Chem. 127, 8393–8396 (2015).

    Google Scholar 

  191. Goesten, M. G., Rahm, M., Bickelhaupt, F. M. & Hensen, E. J. M. Cesium’s off-the-map valence orbital. Angew. Chem. Int. Ed. 56, 9772–9776 (2017).

    CAS  Google Scholar 

  192. Miao, M. S. et al. Anionic chemistry of noble gases: Formation of Mg-NG (NG = Xe, Kr, Ar) compounds under pressure. J. Am. Chem. Soc. 137, 14122–14128 (2015).

    PubMed  CAS  Google Scholar 

  193. Botana, J., Brgoch, J., Hou, C. & Miao, M. Iodine anions beyond −1: formation of LinI (n = 2–5) and its interaction with quasiatoms. Inorg. Chem. 55, 9377–9382 (2016).

    PubMed  CAS  Google Scholar 

  194. Li, X. et al. Stable lithium argon compounds under high pressure. Sci. Rep. 5, 16675 (2015).

    PubMed  PubMed Central  CAS  Google Scholar 

  195. Liu, Z., Botana, J., Miao, M. S. & Yan, D. D. Unexpected Xe anions in XeLin intermetallic compounds. EPL 117, 26002 (2017).

    Google Scholar 

  196. Li, P., Gao, G., Wang, Y. & Ma, Y. Crystal structures and exotic behavior of magnesium under pressure. J. Phys. Chem. C 114, 21745–21749 (2010).

    CAS  Google Scholar 

  197. Dye, J. L. Compounds of alkali metal anions. Angew. Chem. Int. Ed. Engl. 18, 587–598 (1979).

    Google Scholar 

  198. Zurek, E. Alkali metals in ethylenediamine: a computational study of the optical absorption spectra and NMR parameters of [M(en)3δ+∙Mδ−] ion pairs. J. Am. Chem. Soc. 133, 4829–4839 (2011).

    PubMed  CAS  Google Scholar 

  199. Jansen, M. Effects of relativistic motion of electrons on the chemistry of gold and platinum. Solid State Sci. 7, 1464–1474 (2005).

    CAS  Google Scholar 

  200. Karpov, A., Nuss, J., Wedig, U. & Jansen, M. Cs2Pt: A platinide(-II) exhibiting complete charge separation. Angew. Chem. Int. Ed. 42, 4818–4821 (2003).

    CAS  Google Scholar 

  201. Yang, G., Wang, Y., Peng, F., Bergara, A. & Ma, Y. Gold as a 6p-element in dense lithium aurides. J. Am. Chem. Soc. 138, 4046–4052 (2016).

    PubMed  CAS  Google Scholar 

  202. Brgoch, J. & Hermus, M. Pressure-stabilized Ir3− in a superconducting potassium iridide. J. Phys. Chem. C 120, 20033–20039 (2016).

    CAS  Google Scholar 

  203. Dawes, S. B., Ward, D. L., Huang, R. H. & Dye, J. L. First electride crystal structure. J. Am. Chem. Soc. 108, 3534–3535 (1986).

    CAS  Google Scholar 

  204. Dye, J. L. et al. Cavities and channels in electrides. J. Am. Chem. Soc. 118, 7329–7336 (1996).

    CAS  Google Scholar 

  205. Dye, J. L. Electrides: Early examples of quantum confinement. Acc. Chem. Res. 42, 1564–1572 (2009).

    PubMed  CAS  Google Scholar 

  206. Takemura, K. et al. Phase stability of highly compressed cesium. Phys. Rev. B 61, 14399–14404 (2000).

    CAS  Google Scholar 

  207. Zurek, E., Jepsen, O. & Andersen, O. K. Muffin-tin orbital Wannier-like functions for insulators and metals. ChemPhysChem 6, 1934–1942 (2005).

    PubMed  CAS  Google Scholar 

  208. Maksimov, E. G., Magnitskaya, M. V. & Fortov, V. E. Non-simple behavior of simple metals at high pressure. Phys.-Uspekhi 48, 761–780 (2005).

    CAS  Google Scholar 

  209. Schnering, H. G. von & Nesper, R. How nature adapts chemical structures to curved surfaces. Angew. Chem. Int. Ed. Engl. 26, 1059–1080 (1987).

    Google Scholar 

  210. Neaton, J. B. & Ashcroft, N. W. On the constitution of sodium at higher densities. Phys. Rev. Lett. 86, 2830–2833 (2001).

    PubMed  CAS  Google Scholar 

  211. Neaton, J. B. & Ashcroft, N. W. Pairing in dense lithium. Nature 400, 141–144 (1999).

    CAS  Google Scholar 

  212. Rousseau, B. & Ashcroft, N. W. Interstitial electronic localization. Phys. Rev. Lett. 101, 046407 (2008).

    PubMed  Google Scholar 

  213. Marqués, M. et al. Optical and electronic properties of dense sodium. Phys. Rev. B 83, 184106 (2011).

    Google Scholar 

  214. Gatti, M., Tokatly, I. V. & Rubio, A. Sodium: a charge-transfer insulator at high pressures. Phys. Rev. Lett. 104, 216404 (2010).

    PubMed  Google Scholar 

  215. Matsuoka, T. & Shimizu, K. Direct observation of a pressure-induced metal-to-semiconductor transition in lithium. Nature 458, 186–189 (2009).

    PubMed  CAS  Google Scholar 

  216. Pickard, C. J. & Needs, R. J. Dense low-coordination phases of lithium. Phys. Rev. Lett. 102, 146401 (2009).

    PubMed  Google Scholar 

  217. Adebayo, G. A. Ab initio calculations of optical properties of Li and K at high pressures. J. Phys. Chem. Solids 74, 1221–1226 (2013).

    CAS  Google Scholar 

  218. Guillaume, C. L. et al. Cold melting and solid structures of dense lithium. Nat. Phys. 7, 211–214 (2011).

    CAS  Google Scholar 

  219. Rousseau, B., Xie, Y., Ma, Y. & Bergara, A. Exotic high-pressure behavior of light alkali metals, lithium and sodium. Eur. Phys. J. B 81, 1 (2011).

    CAS  Google Scholar 

  220. Marques, M. et al. Crystal structures of dense lithium: a metal-semiconductor-metal transition. Phys. Rev. Lett. 106, 095502 (2011).

    PubMed  CAS  Google Scholar 

  221. Pickard, C. J. & Needs, R. J. Aluminium at terapascal pressures. Nat. Mater. 9, 624–627 (2010).

    PubMed  CAS  Google Scholar 

  222. Martinez-Canales, M., Pickard, C. J. & Needs, R. J. Thermodynamically stable phases of carbon at multiterapascal pressures. Phys. Rev. Lett. 108, 045704 (2012).

    PubMed  Google Scholar 

  223. Zhu, Q., Oganov, A. R. & Lyakhov, A. O. Novel stable compounds in the Mg–O system under high pressure. Phys. Chem. Chem. Phys. 15, 7696–7700 (2013).

    PubMed  CAS  Google Scholar 

  224. Dong, X. & Oganov, A. R. in Correlations in Condensed Matter Under Extreme Conditions: A Tribute to Renato Pucci on the Occasion of his 70th Birthday (eds Angilella, G. G. N. & La Magna, A.) 69–84 (Springer, 2017).

  225. Modak, P. & Verma, A. K. Pressure induced multi-centre bonding and metal–insulator transition in PtAl2. Phys. Chem. Chem. Phys. 21, 13337–13346 (2019).

    PubMed  CAS  Google Scholar 

  226. Naumov, I. I. & Hemley, R. J. Origin of transitions between metallic and insulating states in simple metals. Phys. Rev. Lett. 114, 156403 (2015).

    PubMed  Google Scholar 

  227. Lv, J., Wang, Y., Zhu, L. & Ma, Y. Predicted novel high-pressure phases of lithium. Phys. Rev. Lett. 106, 015503 (2011).

    PubMed  Google Scholar 

  228. Sternheimer, R. On the compressibility of metallic cesium. Phys. Rev. 78, 235–243 (1950).

    CAS  Google Scholar 

  229. Miao, M. S. & Hoffmann, R. High-pressure electrides: The chemical nature of interstitial quasiatoms. J. Am. Chem. Soc. 137, 3631–3637 (2015).

    PubMed  CAS  Google Scholar 

  230. Miao, M. S., Hoffmann, R., Botana, J., Naumov & Hemley, R. J. Quasimolecules in compressed lithium. Angew. Chem. Int. Ed. 56, 972–975 (2017).

    CAS  Google Scholar 

  231. Saunders, M. et al. Incorporation of helium, neon, argon, krypton, and xenon into fullerenes using high pressure. J. Am. Chem. Soc. 116, 2193–2194 (1994).

    CAS  Google Scholar 

  232. Grochala, W. A metastable He–O bond inside a ferroelectric molecular cavity: (HeO)(LiF)2. Phys. Chem. Chem. Phys. 14, 14860–14868 (2012).

    PubMed  CAS  Google Scholar 

  233. Hogness, T. R. & Lunn, E. G. The ionization of hydrogen by electron impact as interpreted by positive ray analysis. Phys. Rev. 26, 44–55 (1925).

    CAS  Google Scholar 

  234. Miao, M. Helium chemistry: react with nobility. Nat. Chem. 9, 409–410 (2017).

    PubMed  Google Scholar 

  235. Liu, Z. et al. Reactivity of He with ionic compounds under high pressure. Nat. Commun. 9, 951 (2018). This work provides a new mechanism explaining how He can be reactive without forming any local chemical bonds, uncovering potential insertion reactions of He with many ionic compounds.

    PubMed  PubMed Central  Google Scholar 

  236. Botana, J. & Miao, M. Helium shows new chemistry not seen anywhere else. Chemistry 2, 466–467 (2017).

    CAS  Google Scholar 

  237. Gao, H., Sun, J., Pickard, C. J. & Needs, R. J. Prediction of pressure-induced stabilization of noble-gas-atom compounds with alkali oxides and alkali sulfides. Phys. Rev. Mater. 3, 015002 (2019).

    CAS  Google Scholar 

  238. Liu, H. Y., Yao, Y. S. & Klug, D. D. Stable structures of He and H2O at high pressure. Phys. Rev. B 91, 014102 (2015).

    Google Scholar 

  239. Bai, Y. et al. Electrostatic force driven helium insertion into ammonia and water crystals under pressure. Commun. Chem. 2, 102 (2019).

    Google Scholar 

  240. Pickard, C. J. & Needs, R. J. Highly compressed ammonia forms an ionic crystal. Nat. Mater. 7, 775–779 (2008).

    PubMed  CAS  Google Scholar 

  241. Liu, C. et al. Multiple superionic states in helium–water compounds. Nat. Phys. 15, 1065–1070 (2019).

    CAS  Google Scholar 

  242. Zhang, J. et al. Rare helium-bearing compound FeO2He stabilized at deep-Earth conditions. Phys. Rev. Lett. 121, 255703 (2018).

    PubMed  Google Scholar 

  243. Fredrickson, D. C. DFT-chemical pressure analysis: Visualizing the role of atomic size in shaping the structures of inorganic materials. J. Am. Chem. Soc. 134, 5991–5999 (2012).

    PubMed  CAS  Google Scholar 

  244. Hubert, H. et al. Icosahedral packing of B12 icosahedra in boron suboxide (B6O). Nature 391, 376–378 (1998).

    Google Scholar 

  245. Deng, N., Yang, G., Wang, W. & Qiu, Y. Structural transitions and electronic properties of sodium superoxide at high pressures. RSC Adv. 6, 67910–67915 (2016).

    CAS  Google Scholar 

  246. Morito, H., Momma, K. & Yamane, H. Crystal structure analysis of Na4Si4−xGex by single crystal X-ray diffraction. J. Alloys Compd. 623, 473–479 (2015).

    CAS  Google Scholar 

  247. Bader, R. F. W. Atoms in Molecules: A Quantum Theory (Oxford Univ. Press, 1990).

  248. Stillinger, F. H. Exponential multiplicity of inherent structures. Phys. Rev. E 59, 48–51 (1999).

    CAS  Google Scholar 

  249. Zurek, E. in Handbook of Solid State Chemistry (ed. Dronskowski, R.) 571–605 (Wiley, 2017).

  250. Jansen, M. Conceptual inorganic materials discovery – a road map. Adv. Mater. 27, 3229–3242 (2015).

    PubMed  CAS  Google Scholar 

  251. Schön, J. C., Doll, K. & Jansen, M. Predicting solid compounds via global exploration of the energy landscape of solids on the ab initio level without recourse to experimental information. Phys. Status Solidi B 247, 23–39 (2010).

    Google Scholar 

  252. Revard, B. C., Tipton, W. W. & Hennig, R. G. in Prediction and Calculation of Crystal Structures: Methods and Applications (eds Atahan-Evrenk, S. & Aspuru-Guzik, A.) 181–222 (Springer, 2014).

  253. Oganov, A. R. Modern Methods of Crystal Structure Prediction (Wiley, 2011).

  254. Lonie, D. C. & Zurek, E. XtalOpt: An open-source evolutionary algorithm for crystal structure prediction. Comput. Phys. Commun. 182, 372–387 (2011).

    CAS  Google Scholar 

  255. Avery, P., Toher, C., Curtarolo, S. & Zurek, E. XtalOpt Version r12: An open-source evolutionary algorithm for crystal structure prediction. Comput. Phys. Commun. 237, 274–275 (2019).

    CAS  Google Scholar 

  256. Goedecker, S. Minima hopping: an efficient search method for the global minimum of the potential energy surface of complex molecular systems. J. Chem. Phys. 120, 9911–9917 (2004).

    PubMed  CAS  Google Scholar 

  257. Amsler, M. & Goedecker, S. Crystal structure prediction using the minima hopping method. J. Chem. Phys. 133, 224104 (2010).

    PubMed  Google Scholar 

  258. Laio, A. & Parrinello, M. Escaping free-energy minima. Proc. Natl Acad. Sci. USA 99, 12562–12566 (2002).

    PubMed  PubMed Central  CAS  Google Scholar 

  259. Schön, J. C. & Jansen, M. First step towards planning of syntheses in solid-state chemistry: Determination of promising structure candidates by global optimization. Angew. Chem. Int. Ed. Engl. 35, 1286–1304 (1996).

    Google Scholar 

  260. Kirkpatrick, S., Gelatt, C. D. & Vecchi, M. P. Optimization by simulated annealing. Science 220, 671–680 (1983).

    PubMed  CAS  Google Scholar 

Download references

Acknowledgements

M.M. and Y.S. acknowledge the support of NSF CAREER award 1848141 and computational resources provided by XSEDE (TG-DMR130005). M.M. also acknowledges the support of ACS PRF 59249-UNI6. E.Z. acknowledges the support of NSF (DMR-1827815) and DOE (DE-SC0020340). H.L. acknowledges financial support from NSAF U1930402 and computational resources from the Beijing Computational Science Research Center.

Author information

Authors and Affiliations

  1. Department of Chemistry and Biochemistry, California State University, Northridge, Northridge, CA, USA

    Maosheng Miao & Yuanhui Sun

  2. Department of Chemistry, State University of New York at Buffalo, Buffalo, NY, USA

    Eva Zurek

  3. Beijing Computational Science Research Center, Beijing, China

    Haiqing Lin

  4. Department of Physics, Beijing Normal University, Beijing, China

    Haiqing Lin

Authors
  1. Maosheng Miao
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Yuanhui Sun
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Eva Zurek
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Haiqing Lin
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

M.M. conceived the synopsis of the article, proposed the conceptual framework and wrote the first draft. M.M. and E.Z. made major revisions to the article. E.Z. wrote Box 1 and made major contributions to the section on hydrides. Y.S. made Table 1, Fig. 1, contributed to the literature search and helped with the other figures. H.L. supported and discussed the research and writing.

Corresponding author

Correspondence to Maosheng Miao.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Miao, M., Sun, Y., Zurek, E. et al. Chemistry under high pressure. Nat Rev Chem 4, 508–527 (2020). https://doi.org/10.1038/s41570-020-0213-0

Download citation

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41570-020-0213-0

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing