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Updated: Jun 19, 2026

Synthesis and Microdiffraction at Extreme Pressures and Temperatures
Published on: October 7, 2013
Structural prediction and phase transformation mechanisms in calcium at high pressure
Yansun Yao1, Dennis D Klug, Jian Sun
1Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, K1A 0R6, Canada.
Abstract:
High-pressure phase transformations of Ca are studied using the metadynamics method to explore the anharmonic free-energy surface, together with a genetic algorithm structural search method to identify lowest enthalpy structures. Disagreement between theory and experiment regarding the structure of Ca in the pressure range 32-119 GPa is partially resolved by the demonstration of different phase transition behavior at 300 K from that at low temperatures. A new lowest enthalpy I4(1)/amd structure is obtained with both methods with an estimated superconducting critical temperature in agreement with experiment.
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