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Department of Chemistry Choong-Shik Yoo

Professor of Chemistry and Institute of Shock Physics

Fulmer 549 & Shock Physics 242
Pullman, WA 99164


(509) 335-2712



Post-Doctoral Study, 1986-1989
Washington State University, Pullman, WA


Ph.D. Physical Chemistry, 1986
University of California, Los Angeles, CA


Professor Yoo received his Ph.D. in Physical Chemistry in 1986 from UCLA and then spent three years at WSU as a Postdoctral Research Fellow. In 1989, he joined the Lawrence Livermore National Laboratory where he led a large multi-disciplinary research group for High Pressure Physics Program. After a long career at the national laboratory, in 2007 he returned to WSU as a new faculty member at the Chemistry Department and the Institute for Shock Physics. Professor Yoo won twice in 1995 and 2006 the DOE awards for Excellence in Weapons Materials Research. He currently serves as US Regional Editor for High Pressure Research, and is a member of American Chemical Society, American Physical Society, American Geophysics Union, and Materials Research Society.Our group focuses on Extreme Materials Research at the pressure-temperature conditions of the Earth’s and Joviant planetary interiors, where materials alter their properties in many fundamental ways and, thus, provide exciting opportunities for one to discover new materials, novel phenomena, and exotic states of matter- not present at the ambient condition. Examples are numerous, including recently discovered stishovite-like carbon dioxide polymer, metallic hydrogen, superconducting lithium, superionic water, novel metal nitrides, superionic lithium nitrides, and many others. High-pressure research will ultimately establish a new Periodic Table of the elements and compounds with completely redefined chemical and physical properties. Our extreme materials research helps unveil such a new materials order and understand its governing rules.Our research utilizes modern static and dynamic high-pressure technologies coupled with the state-of-the-art laser spectroscopy and the x-ray diffraction and x-ray spectroscopy at national synchrotron facilities. Because materials often behave differently under static and dynamic compressions, we emphasize an integrated approach of static and dynamic experiments over extended ranges of pressure, temperature, and strain rate.Materials of our research interest range from fundamental materials of quantum solids, molecular solids, covalent and ionic solids, and f-and d-electron metals to functional materials such as reactive nanoparticles, hydrogen storage materials, strongly correlated systems, and high energy density solids. Because of its multi-disciplinary nature of high-pressure materials research, we often collaborate with theorists and scientists well beyond our group and Chemistry department, including Institute for Shock Physics, Materials Science Program, and National Laboratories.


Phase diagram and transformation of iron pentacarbonyl to nm layered hematite and carbon- oxygen polymer under pressure, YoungJay Ryu, Minseob Kim, and Choong-Shik Yoo, Scientific Reports (2015) DOI:10.1038/srep15139.

Pressure-induced symmetry lowering transition in dense nitrogen to layered polymeric nitrogen (LP-N) with colossal Raman intensity, D. Tomasino, M. Kim, J. Smith, and C. S. Yoo, Phys. Rev. Lett. 113, 205502 (2014).

Solidification and fcc- to Metastable hcp- Phase Transition in Krypton under Variable Compression Rates, Jing-Yin Chen, Choong-Shik Yoo, William J. Evans, Hanns-Peter Liermann, Hyunchae Cynn, Minseob Kim, and Zsolt Jenei, Phys. Rev. B 90, 144104 (2014).

Hydrogen Bonding Induced Proton Exchange Reactions in Dense D2-NH3 and D2-CH4 Mixtures, Gustav M. Borstad and Choong-Shik Yoo, J. Chem. Phys. 140, 044510 (2014).

Polyamorphism and Pressure Induced Metallization at the Rigidity Percolation Threshold in Densified GeSe4 Glass, Bora Kalkan, Ranga P. Dias, Choong-Shik Yoo, Simon M. Clark, and Sabyasachi Sen, J. Phys. Chem. C 118, 5110 (2013).

Phase Diagram of Ammonium Nitrate, Mihindra Dunuwille and Choong-Shik Yoo, J. Chem. Phys. 139, 214503 (2013).

Transformation and Structure of Silicate-like CO2-V, Choong-Shik Yoo, Minseob Kim, Wolfgang Morgenroth, Peter Liermann, Phys. Rev. B. 87, 214103 (2013).

Low-Temperature Superconducting Phase and Magnetic Ordering in Highly Disordered Carbon Disulfide under High Pressure, Ranga Dias, Choong-Shik Yoo, Viktor V. Struzhkin, Minseob Kim, Takaki Muramatsu, Takahiro Matsuoka, Yasuo Ohishi, and Stainislav Sinogeikin, Proc. Nat. Acad. Sci. 110, 11720 (2013).

Solidification and Crystal Growth of Highly Compressed Hydrogen and Deuterium: Time-Resolved Study under Ramp Compression in Dynamic-Diamond Anvil Cell, Dane Tomasino and Choong-Shik Yoo, Appl. Phys. Lett. 103, 061905 (2013).

Physical and Chemical Transformations of Highly Compressed Carbon Dioxide at Bond Energies, Choong-Shik Yoo, Phys. Chem. Chem. Phys. 15, 7949 (2013).

Dynamic Responses of Reactive Metallic Structures under Thermal and Mechanical Ignitions, Haoyan Wei and Choong-Shik Yoo, J. Mater. Res. 27, 2705 (2012).

“Stubborn” Triaminotrinitrobenzene (TATB): Unusually high chemical stability of a molecular solid to 150 GPa, Alistair Davidson, Ranga P. Dias, Dana M. Dattelbaum, and Choong-Shik Yoo, J. Chem. Phys. 135, 174507 (2011); doi: 10.1063/1.3658385

Time- and angle-resolved x-ray diffraction to probe structural and chemical evolution during Al-Ni intermetallic reactions, Choong-Shik Yoo, Haoyan Wei, Jing-Yin Chen, Guoyin Shen, Paul Chow, and Yuming Xiao, Rev. Sci. Instrum. 82, 113901 (2011).

High Density Amorphous Ice above the Critical Temperature, Jing-Yin Chen and Choong-Shik Yoo, Proc. Nat. Acad. Sci., USA 108, 7685 (2011).

Novel 2D and 3D Extended Solids and Metallization of Compressed XeF2, Minseob Kim, Mathew Debessai, and Choong-Shik Yoo, Nature Chem. 2, 784 (2010)