HIGHLIGHTS

The 24th International Conference on the Science of Compression in Condensed Matter (SCCM 2025), hosted by the American Physical Society Topical Group on Compression of Condensed Matter, was held from June 22-27, 2025 at the Washington Hilton Hotel in Washington, DC. For the first time, the conference addressed all timescales of compression, from static to dynamic to shock. In addition to a complete range of technical sessions, a series of tutorials were presented by experts in the various topical areas covered by the meeting.  SCCM 2025 also included a poster session and an Early Career Student Symposium. The complete program is available here.

CDAC Director Russell Hemley delivered the first presentation of the meeting, New Materials With Extreme Properties and Performance From Compression of Condensed Matter in the Plenary Session, “The Magical World of Static and Dynamic Compression.”  CDAC Partner Dana Dlott also presented a plenary lecture, High Throughput Tabletop Shock Experiments With Applications to Energetic Materials in the session “All About Energetic Materials.”

CDAC was well represented at the meeting across a wide variety of topical areas.  Presentations including authors affilliated with CDAC are listed below, with CDAC presenters in bold, and CDAC coauthors in parentheses:

A01-1  Russell Hemley :  New Materials With Extreme Properties and Performance From Compression of Condensed Matter

G01-1  Dana Dlott :  High Throughput Tabletop Shock Experiments With Applications to Energetic Materials 

L02-1  Zhuanling Bai :  High Pressure Effects on an Octa-Hydrated Curium Complex : An Experimental and Theoretical Investigation 
(M. Reddington, E. Zurek)

H08-2  Hannah Bausch  :   Thermoelasticity of MgO up to 400 GPa Using Shock-Ramp Compression on the Z Machine
(T. Abbott, S. Jacobsen)

L08-2  Peter Celliers  :  Entropy Differences Between H₂ and D₂ and the Phase Diagram of Hydrogen Isotopes
(R. Hemley)

Z05-3  Alisha Clark  :  Insights Into the Fate of Volatile Species During the Planetary Life Cycle from Dynamic Compression Experiments
(T. Abbott, S. Jacobsen)

H02-4  Dana Dlott :  Hot-Spot Growth in Plastic-Bonded Explosives (PBX) Seen With High Time and Space Resolution

D02-2  Anukriti Ghimire  :  Phase Boundaries, Isotope Effect, and Superconductivity of Lithium Under Pressure
(E. Zurek)

Poster 72 Lindsay Harrison :  Effect of Water on Shockless Ramp Compression of SiO₂ to Upper Mantle Pressure
(S. Jacobsen)

Poster 66  Masashi Kimura  :  Effects of Anharmonicity on Superconducting Y-Ca-H Systems
(E. Zurek)

Poster 23  Ravhi Kumar  :  Enhancement of Seebeck Coefficient and Thermoelectric Efficiency in Mn-Doped SnTe Under Compression

V06-2  Eduardo de Toledo Poldi  :  Compression of Kiatev Quantum Spin Liquid Candidate Na₃Co₂SbO₆ to Megabar Pressures
(Z. Liu, R. Kumar, R. Hemley)

W-06  Danae Polsin  :  The Electride Nature of Ramp-Compressed Sodium in the Terapascal Regime
(E. Zurek)

Jo5-4  Stefano Racioppi  :  Powder X-ray Diffraction Assisted Evolutionary Algorithm for Crystal Structure Prediction
(E. Zurek)

K02-3  Roma Ripani  :  Compression of Hydrazine to Above 200 GPa
(F. Safari, M. Ahart, Z. Liu, S. Gramsch, R. Hemley)

N01-3   Siva Valluri :  Role of Nanostructural Features in Shock-Initiated Reactivity of Milled Composite
(D. Dlott)

V06-1  Kui Wang  :  Superconductivity and Novel Electron Transport of Elemental Superconductors Under Pressure
(R. Hemley)

L03-4  Charles Zoller  :  High Pressure Behavior of the D₂/H₂ – CO₂ System
(M. Ahart, R. Hemley)

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Nanomaterials—materials with two dimensions below 100 nanometers and a thickness of just a few atoms—can exhibit extraordinary properties for technologies like advanced batteries, catalysis, and quantum computing. Most materials today, however, are made from just one or two elements, limiting how adaptable and robust they can be. High-entropy materials, on the other hand, combine five or more different elements together in a homogeneous substance with a defined crystal structure. This chemical diversity, known as configurational entropy, is predicted to make these materials exceptionally stable and resistant to degradation. But making high-entropy materials that remain stable on the nanoscale has been incredibly challenging. In reality, these complex structures often break apart or separate into different phases, especially when trying to make them just a few atoms thick. This has held back their promise in real-world applications.

A paper published recently in the journal Science involving a CDAC collaboration now reports that novel pressure-induced entropic transformations in new high-entropy oxide nanoribbon material lead to resilience even in the harshest environments : temperatures up to 1,000°C, pressures up to 12 GPa, and prolonged exposure to strong acids and bases for up to 7 days.

In this work, a group of researchers from the University of Illinois Chicago, focusing on finding the right chemistry for high entropy oxide stability, has now devised a template-based approach for nanoparticle synthesis using metal sulfide flakes. These flakes acted as a seed for the controlled growth of high-entropy oxide nanoribbons (1D-HEO), preventing phase separation and ensuring all five metal elements remained evenly mixed (Fig. 1, Top).  Through targeted adjustments in the the reaction conditions, the synthesis process resulted in over two orders of magnitude improved control on the width of the nanoribbons—from nanometers to tens of micrometers—while maintaining exceptional uniformity.  This approach not only resulted in a new nanomaterial, but it also allowed an investigation of the formation process and structural evolution in real time. Structural studies using X-ray diffraction to confirm the 1-D structure (Fig. 1, Middle) were carried out at ambient pressure at Northwestern University, while the HPCAT sector at the Advanced Photon Source provided facilities for high pressure diffraction measurements.  Computational simulations of this complicated chemistry provided crucial information on the evolution and transformations of the HEO nanoribbons.

High-pressure experiments reveal an intriguing transformation of the 1D-HEO nanoribbons from orthorhombic to cubic structures at 15 gigapascals followed by the formation of fully amorphous HEOs above 30 gigapascals, which are recoverable to ambient conditions (Fig. 1, Bottom). These transformations introduce additional entropy (structural disorder) into the system at high pressure, in addition to the configurational entropy arising from the number of different transition metals mixing on the one metal site in the structure. This finding offers a way to create low-dimensional, resilient, and high-entropy materials.

The nanoribbons produced by this synthetic route are not only more resilient than conventional materials but also highly promising for practical applications. Unlike traditional high-entropy materials that require expensive high-temperature casting, these nanoribbons can be 3D-printed or spray-coated—a scalable, cost-effective approach for real-world uses, from ultra-robust coatings to next-generation energy storage. This work was a collaborative study, led at University of Illinois Chicago, with a team spanning mechanical engineering, chemistry, physics, and civil and materials engineering, with partners from Stockholm University, the University of Washington, and Argonne National Laboratory.

Shahbazi, H., et al. Resiliency, morphology, and entropic transformations in high-entropy oxide nanoribbons.  Science  388, 950-956 (2025). [DOI : 10.1126/science.adr5604]

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CDAC Academic Partner Steven Jacobsen (Northwestern University) presented a plenary lecture and graduate student Hannah Bausch presented a poster detailing her research at the recent Z Fundamental Science Program (ZFSP) Workshop, held August 6-9, 2024 in Albuquerque, NM, home of Sandia National Laboratories and Sandia’s Z Machine. The purpose of this annual workshop is to showcase recent shock compression work performed on Sandia’s Z machine within the ZFSP and to provide guidelines from Z facility personnel on the preparation of proposals for instrument time to carry out basic research in the area of dynamic compression with pulsed power sources.

Steve’s presentation was entitled “Origin of the Ultra-Low Velocity Zones Atop Earth’s Core-Mantle Boundary.”  Hannah’s poster was entitled “Shock-Ramp Compression of (Mg,Fe)O up to Earth’s Core Conditions. CDAC-supported work at Northwestern employs Sandia’s Z machine with specially designed pulse sequences and unique experimental configurations to reach thermodynamic states that are not accessible with either static compression or other dynamic compression methods.  Steve’s and Hannah’s work addresses the properties and evolution of complex structures at Earth’s core-mantle boundary region that have been observed through anomalies in seismic data.

For more on the ZFSP and to view the workshop agenda, see the workshop website.

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Developing equations of state (EOS) for mixtures of gases presents a variety of technical challenges arising from the differences in the physical properties of the components. In the case of the H₂-He system, despite the apparent chemical simplicity of these two-electron systems, the behavior of their mixtures is complicated by nonideal mixing and phase transitions in H₂ at high pressures.

In new work carried out through a collaboration between Sandia National Laboratories and UIC, accurate pressure-density EOS for hydrogen-helium mixures have been determined to 44 GPa, representing greater than fourfold compression. Data obtained using both hypervelocity gas guns and Sandia’s Z machine on precompressed samples, in combination with Brillouin spectroscopy on samples under pressure in the diamond anvil cell,¹ have resulted in equations of state for H₂-He mixtures with less than 10% uncertainty in the density (Fig. 1). This allows discrimination between various possible equation of state models for H₂-He mixtures as well as the benchmarking of proposed planetary models. This work has important implications for understanding the dynamics of gas giant planets and their satellites, as well as the development of experimental techniques on shock compression platforms.

The lead author on this work is  Sakun Duwal, a former CDAC graduate student and now a Principal Technical Staff Member in the Dynamic Material Properties (DMP) Department at Sandia National Laboratories. The DMP research program  is led by Chris Seagle, also a former CDAC graduate student, from the University of Chicago.

¹  Zoller, C. M., M. Ahart, S. Duwal, R. C. Clay III, C. T. Seagle, Y. J. Ryu, S. Tkachev, S. Chariton, V. Prakapenka, and R. J. Hemley, Accurate equation of state of H₂-He binary mixtures up to 5.4 GPa. Physical Review B 108, 224112 (2023).
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Duwal, S., R. C. Clay III, M. D. Knudson, J. Boerner, K. Cochrane, J. Usher, D. Dolan, B. Farfan, C. de La Cruz, J. Banasek, C. T. Seagle, R. Hacking, S. Payne, C. Zoller, M. Ahart, and R. J. Hemley, Extreme compression of planetary gases: High-accuracy pressure-density measurements of hydrogen-helium mixtures above fourfold compression. Physical Review B, 109, 104102 (2024).

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CDAC scientists presented an array of discoveries in condensed matter physics, from superconductivity to energetic materials and quantum matter, at the 2024 American Physical Society March Meeting, held March 4-8 in Minneapolis, MN. The meeting included eight presentations involving CDAC students, postdocs, research staff, faculty and collaborators.  CDAC personnel contributed to a variety of technical sessions, and addressed the Thermomechanical Extremes and Chemical and Material Extremes thrusts in the CDAC scientific program.

CDAC Director Russell Hemley gave an invited presentation, “Toward Ambient Superconductivity” in the session on Frontiers in Static and Dynamic Compression of Condensed Matter.  CDAC academic partner Eva Zurek is chair-elect of the APS Division of Computational Physics and helped organize this as well as a number of other sessions at the meeting related to theoretical and computational approaches.

CDAC academic partner Steve Jacobsen and graduate student Hannah Bausch (Northwestern) were a co-authors on the presentation, “Combined Self-Consistent DFT+U and Quantum Monte Carlo Investigation of the High Pressure Spin Transition in Ferropericlase” (Abstract N20.00005), presented by Joshua Townsend, a former CDAC graduate student at Northwestern and currently a staff scientist at Sandia National Laboratories.

Adam Denchfield (UIC) Candidate High-T_c Superconductors in a Class of Quaternary Hydrides
Co-Authors : R.J. Hemley, H. Park
(Abstract N15.00004)

Husam Farraj (UIC). Structural Phase Transitions in KC₈ under High Pressure
Co-Authors : R.J. Hemley, J. Cabana, M. Aihaiti, H.P. Liermann, K. Glazyrin, Y. Meng
(Abstract G20.00007)

Clayton Halbert (UIC). High-Pressure Structure, Equation of State, and superconductivity of Bi_0.5Sb_1.5Te₃: Observation of a Novel Bi-Sb-Te Alloy
Co-Authors: N.P. Salke, L. Deng, S. Song, X. Shi, Z. Ren, C.W Chu, R.J. Hemley
(Abstract G20.00002)

Russell Hemley (UIC, Invited). Toward Ambient Superconductivity
(Abstract B45.00002)

Alexander Mark (UIC). Phase Sensitive Detection Applied to Superconducting Transport Measurements
Co-Authors: N.P. Salke, M. Ahart, R.J.Hemley
(Abstract G20.00004)

Roma Ripani (UIC). Vibrational Dynamics of Hydrazine to 50 GPa
Co-Authors: F. Safari, Z. Liu, M. Aihaiti, S.A. Gramsch, R.J. Hemley
(Abstract M20.00012)

Nilesh Salke (UIC). Electrical Resistance and Magnetic Susceptibility Evidence for Near Ambient Superconductivity in Nitrogen-Doped Lutetium Hydride
Co-Authors: A.C. Mark, M. Ahart, R.J. Hemley
(Abstract G20.00006)

Eva Zurek (Buffalo). Theoretical Design of Light-Element Superconductors                
(Abstract F20.00002)

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CDAC science was once again well represented this year at the annual Stewardship Science Academic Programs (SSAP) Symposium, which was held in Arlington, Virginia on February 21-22, 2024. Students from UIC and all six CDAC academic partner groups presented posters on their research, and CDAC Director Russell Hemley gave an overview of the Center’s current progress and a preview of the next phase of CDAC, which is set to begin on July 1, 2024.

The SSAP Symposium brings together representatives from DOE/NNSA-sponsored Centers of Excellence and individual grant holders in the areas of Materials at Extreme Conditions, Low Energy Nuclear Science, and High Energy Density Physics. At one time the only Center devoted to the study of materials in extreme conditions, CDAC is now joined by several other materials centers with a diversity of scientific programs and research approaches. Students from across the SSAP also had an opportunity to network with representatives from the NNSA laboratories to explore future postdoctoral opportunities.

Keynote speaker David Hoaglund, Executive Principal Assistant Deputy Administrator for Defense Programs within DOE/NNSA, outlined some of the important implications for the field of stewardship science in an increasingly unpredictable geopolitical landscape. In his address, Mr. Hoagland drew attention to the key contributions to international security that are provided by a robust commitment to scientific research and development in this field. The full agenda for the symposium is available at the SSAP Symposium website.

CDAC students attending the SSAP Symposium this year, along with their poster titles are as follows:

Hannah Bausch (Northwestern) : Shock-Ramp Compression of (Mg,Fe)O up to Earth’s Core Conditions
Co-Authors : J. P. Townsend, S. Duwal, C. A. McCoy, J.-P. Davis, T. Abbott, A. N. Clark, S. D. Jacobsen

Audrey Berlin (Utah) : High Pressure Effects of Light Elements on Fe₅₀Ni₅₀ Plasticity
Co-Authors : E. E. Ledoux, C. Kiessner, L. Miyagi

Brian Blankenau (UIUC) : Magnetostructural Phase Transformations in Ni₅₀ Mn_50-x In_x Shape Memory Alloys
Co-Authors : T. Su, R. Kumar, D. Popov, E. Ertekin

Husam Farraj (UIC): Study of a Novel Cathode Material by Raman Scattering, and X-ray and Neutron Diffraction Under Various P-T Conditions
Co-Authors: N. Sunariwal, I. Roy, J. Hirtz, R. Kumar, M. Diamond, M. Ahart, M. Lang, J. Cabana, R. Hemley

Clayton Halbert (UIC) : High-Pressure Structure and Equation of State of Bi_0.5Sb_1.5Te₃:Observation of Superconductivity in a Novel Bi-Sb-Te Alloy
Co-Authors: N. Salke, A. Manayil-Marathamkottil, H. Farraj, M. Ahart, L. Deng, C. Chu, S. Song, X. Shi, Z. Ren, H. Liermann, Y. Meng, K. Glazyrin, R. Hemley

Masashi Kimura (Buffalo) High-Pressure Searches of Ternary YCaH_n Systems
Co-Author: E. Zurek

Jacob Minnette (Tennessee) : Coupled Extremes in Nuclear Materials
Co-Authors: J. Hirtz, W. Cureton, C. Park, I. Schubert, I.Ivanov, A. Berlin, C. Kiessner, L. Miyagi, M. Lang.

Allison Pease (Michigan State) : Liquid Structure of Iron-Nitrogen-Carbon Alloys Within the Cores of Small Terrestrial Bodies
Co-Authors : J. Liu, J. Piper, M. Lv, Y. Kono, S. Dorfman

Morgan Reddington (Buffalo) : Tritium Adsorption and Transfer on Pure and Tin Defective Zirconium
Co-Authors: H. P. Paudel, E. Zurek, D. N.Tafen, Y. Duan

Roma Ripani (UIC) : Single Crystal X-ray Diffraction, Raman and Infrared Study of Hydrazine to 50 GPa
Co-Authors : F. Safari, S. Gramsch, M. Ahart, Z. Liu, R. Hemley

Charlie Zoller (UIC) : Optical Properties of Aluminum Under Pressure and Temperature
Co-Authors : S. Duwal, Z. Liu, R. Clay, S. Chaudhuri, D. Dolan, C. Seagle, R. Hemley

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The 7th annual FQM school focused on High Pressure Synthesis and Measurement, areas of research of great interest to CDAC.  As a result, CDAC made a strong showing at the school and accompanying workshop.

CDAC Students Abdul Haseeb Manayil Marathamkottil, Eduardo Poldi, Husam Farraj and Roma Ripani attended the event while CDAC’s director Russell Hemley contributed to the Workshop Program by presenting a talk entitled ‘Progress on High Tc Hydride Superconductivity.’

FQM 2024 targeted students who are starting to work with either high pressure experiments or sample growth and included a combination of fundamental materials synthesis instruction as well as lectures on experimental techniques and practice from invited speakers with diverse expertise.

The school covered diamond anvil cell techniques in a practical way, with a focus on various types of DAC measurements available at universities as well as synchrotron and neutron facilitiess. Discussion sessions engaged students and other early early career scientists on topics of current interest.

The Workshop on the final day featured a series of lectures that highlighted topics at the
forefront of quantum materials under pressure.

See FQM’s website for more information

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CDAC was well represented at the American Geophysical Union Fall Meeting held in San Francisco, CA from December 11-15. Four graduate students and one CDAC faculty partner presented their CDAC-supported research focused on the behavior of materials at extreme conditions, highlighting topics in both the Thermomechanical Extremes and Chemical and Material Extremes thrust areas of the CDAC scientific program.

Graduate students from several CDAC groups pursue research on Earth and planetary materials.  The complex, often multi-phase and non-stoichiometric nature of these materials provides a rich training ground for developing an understanding of material behavior in extreme conditions.

Hannah Bausch (Northwestern) presented a poster outlining her work on the shock-ramp compression of (Mg,Fe)O on Sandia’s Z machine, and was also a co-author on Luisa Chavarria’s (Michigan State) poster presentation on the incorporation of sodium into (Mg,Fe)O at lower mantle conditions.

Allison Pease (Michigan State) presented a poster on the thermal equation of state of transition metal-bearing CaSiO₃ and its implications for large, low shear velocity zones in the lower mantle, and Audrey Berlin (Utah) gave an oral presentation on the contributions of light elements, pressure, temperature and strain on the formation of the L10 FeNi alloy in a session on iron and iron-bearing phases in planetary interiors.

CDAC Academic Partner Lowell Miyagi (Utah) also gave a poster on the recent development of a novel dynamic diamond anvil cell for high strain rate measurements during radial diffraction measurements. This work is part of a collaboration with the Materials Physics and Applications Group at LANL headed by Blake Sturtevant.

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Microcrystalline zirconium carbide exhibits lattice expansion due to defect accumulation in two distinct regimes, which differs from the behavior of oxide materials such as CeO₂. This contrasting behavior is observed across different grain sizes.

CDAC graduate student Jacob Minnette, from the group of Academic Partner Maik Lang at the University of Tennessee, along with collaborators from the Lang group, Oak Ridge National Laboratory, HPCAT, and the GSI Helmholzzentrum and the Technische Universität in Darmstadt, Germany, have published the results of important new work on the behavior of zirconium carbide under heavy ion irradiation. This paper is highlighted on the cover of the issue of the Journal of Applied Physics in which it appears.

Zirconium carbide (ZrC) is a material that falls within the broader classification of ultra-high temperature ceramic (UHTC) compounds. These materials possess thermomechanical properties that are of interest for a wide variety of emerging energy and aerospace technologies, which often have operating conditions characterized by extreme conditions. In this work, ZrC was studied with synchrotron X-ray diffraction after exposure to energetic heavy ions. Investigations of materials under such intensely ionizing radiation enables a glimpse of their behavior in conditions far from thermodynamic equilibrium.

The effect of irradiation on such ceramic materials is typically concentrated within small point-like defects that lead to crystal lattice swelling and the accumulation of strain, which reaches a saturation limit above a critical ion fluence. In ZrC exposed to 946 MeV Au ions, an unexpected and complex multi-stage defect accumulation trend comprising of initially rapid lattice swelling takes place, followed by saturation, before a secondary linear swelling regime is observed. Lattice swelling then continues to increase linearly under irradiation up to the highest fluence evaluated in this study, 6×10¹³ ions/cm².

The origin of this behavior likely originates from the hypostoichiometric nature of ZrC, which is typical of many UHTC compounds. This swelling mechanism was consistently observed for samples prepared with different synthesis methods and is distinct from what is observed with cerium dioxide irradiated under identical conditions (Fig. 1). This study highlights the fact that materials can respond very differently to extreme environments, and that studying defect accumulation under energetic heavy ion irradiation is an important step in the development of more robust materials for energy-related applications.

Minnette, J., E. Williams, W. Cureton, A. Solomon, E. O’Quinn, M. Kurley, R. D. Hunt, C. Park, I. Schubert, C. Trautmann, and M. Lang, Response of ZrC to swift heavy ion irradiation. Journal of Applied Physics, 134, 185901 (2023).

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The 14th Z Fundamental Science Program (ZFSP) Workshop Fundamental Science with Pulsed Power was hosted by Sandia National Laboratories at the Hotel Analuz in Albuquerque, NM on August 9-11, 2023.  CDAC was represented by Academic Partner Steven Jacobsen and graduate student Hannah Bausch from Northwestern University, and graduate student Charlie Zoller from UIC.

Jacobsen gave a plenary talk titled “Origin of the Ultra-Low Velocity Zones Atop Earth’s Core-Mantle Boundary,” which outlined recent progress following a series of shots at Z carried out as part of Hannah Bausch’s PhD research. She also presented a poster at the Workshop, “Shock-Ramp Compression of (Mg,Fe)O up to Earth’s Core Conditions.”  Zoller’s presentation, “Aluminum Reflectance Measurements Using the Diamond Anvil Cell,” reported results obtained at the Frontier Infrared Spectroscopy beamline at the National Synchrotron Light Source, Brookhaven National Laboratory.

The goal of the ZFSP Workshop is to provide an opportunity for current and prospective users at Z to  to discuss research directions and formulate new ideas for collaborative work on Z. Research directions currently supported by the ZFSP research areas are Astrophysics, Planetary Science, Materials Physics, and Magnetized High Energy Density Science relevant to Magnetized Inertial Fusion.

The scientific program and details on presentations for the breakout sessions are available on the workshop website.

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What determines the structures of simple metals has been a subject of a longstanding debate among researchers, and findings from a new study appearing in the Proceedings of the National Academy of Sciences add new information to consider in the discussion.

By analyzing the electronic properties of metals in various lattices over a broad range of sizes and geometries, CDAC Director Russell Hemley and collaborators shifted from a “physics” band-structure point of view to a “chemical” perspective to find highly complex structures that emerge at high pressures in these materials. This has led to a new theory that can explain why a particular structure is favored for almost all metals in the periodic table.

“This theory is based on our finding that the electrons in many metals occupy what we call quasi-atom orbitals — the local quantum orbitals centered at the voids between the atoms. In large measure, it is the chemical interactions between localized electrons that control the structure of the metals,” Hemley said.

The result contrasts with the traditional view that structures and other properties are determined by the extended electronic states, which behave close to what is known as a free electron gas. However, the structure preference of classes of metals across the periodic table cannot be explained by this “physics,” or band structure point of view.

One reason the research team is particularly excited about this work is that the idea originated from the need for a simple “chemical’ explanation for the existence of high-pressure electrides, a surprising phenomenon that includes for example the fact that some alkali metals become transparent insulators under pressure. The findings have implications for the behavior of chemically complex materials, including alloys, intermetallics, hydrides, ionic compounds and two-dimensional materials.

“This is an example of how the study of matter under extreme conditions can inform us about chemistry and materials under normal, or more familiar conditions. Thus studies of materials at high pressure can reveal chemical features that might be otherwise neglected,” Hemley said.

Sun, Y., L. Zhao, C. J. Pickard, R. J. Hemley, Y. Zheng, and M. Miao, Chemical interactions that govern the structures of metals. Proceedings of the National Academy of Sciences USA, 120, e2218405120 (2023).

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The Center is pleased to report that as of September 1st, 2022, the following papers have been cited 5,563 times since CDAC was founded in 2003:

1. Ahart, M., M. Somayazulu, P. Dera, H.-k. Mao, R. E. Cohen, R. J. Hemley, R. Yang, H. P. Liermann, and Z. Wu, Origin of morphotropic phase boundaries in ferroelectrics. Nature 451, 545-548 (2008). —839 citations.
2. Somayazulu, M., M. Ahart, A. K. Mishra, Z. M. Geballe, M. Baldini, Y. Meng, V. V. Struzhkin and R. J. Hemley, Evidence for Superconductivity Above 260 K in Lanthanum Superhydride at Megabar Pressures. Physical Review Letters 122, 027001 (2019). —823 citations.
3. Mao, W. L., H.-k. Mao, P. Eng, T. P. Trainor, M. Newville, C. C. Kao, D. Heinz, J. Shu, Y. Meng and R. J. Hemley, Bonding changes in compressed superhard graphite. Science 302, 425-427 (2003). —653 citations.
4. Li, Q., Y. Ma, A. R. Oganov, H. Wang, H. Wang, Y. Xu, T. Cui, H.-k. Mao, and G. Zhou, Superhard monoclinic polymorph of carbon. Physical Review Letters 102, 175506 (2009). —561 citations.
5. Gregoryanz, E., C. Sanloup, M. Somayazulu, J. Badro, G. Fiquet, H.-k. Mao and R. J. Hemley, Synthesis and characterization of a binary noble metal nitride. Nature Materials 3, 294-297 (2004). —550 citations.
6. Young, A. F., C. Sanloup, E. Gregoryanz, S. Scandolo, R. J. Hemley and H.-k. Mao, Synthesis of novel transition metal nitrides IrN2 and OsN2. Physical Review Letters 96, 155501 (2006). —543 citations.
7. Liu, H., I. I. Naumov, R. Hoffmann, N. W. Ashcroft, and R. J. Hemley, Potential high-Tc superconducting lanthanum and yttrium hydrides at high pressure. Proceedings of the National Academy of Sciences USA 114, 1704505114 (2017). —530 citations.
8. Angel, R., M. Bijak, J. Zhao, G. D. Gatta, and S. D. Jacobsen, Effective hydrostatic limits of pressure media for high-pressure crystallographic studies. Journal of Applied Crystallography 40, 26-32 (2007). —506 citations.
9. Zhang, W., A. R. Oganov, A. F. Goncharov, Q. Zhu, S. E. Boulfelfel, A. O. Lyakhov, E. Stavrou, M. Somayazulu, V. B. Prakapenka, and Z. Konôpková, Unexpected stable stoichiometries of sodium chlorides. Science 342, 1502-1505 (2013). —433 citations.
10. Struzhkin, V. V., B. Militzer, W. L. Mao, H.-k. Mao and R. J. Hemley, Hydrogen storage in clathrates. Chemical Reviews 107, 4133-4151 (2007). —402 citations.

Altogether over 1700 papers have been published as a direct result of CDAC funding. View all of them here.

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