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arXiv · cond-mat/9610149

Phonon Softening and Elastic Instabilities in the Cubic-to-Orthorhombic Structural Transition of CsH

A. M. Saitta·D. Alfe`·S. de Gironcoli·S. Baroni
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Abstract

The cubic-to-orthorhombic structural transition occurring in CsH at a pressure of about 17 GPa is studied by ab initio calculations. The relative stability of the competing structures and the transition pressure are correctly predicted. We show that this pressure-induced first-order transition is intimately related to a displacive second-order transition which would occur upon application of a shear strain to the (110) planes. The resulting instability is rationalized in terms of the pressure-induced modifications of the electronic structure.

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A. M. Saitta, D. Alfe`, S. de Gironcoli, S. Baroni. 1996-12-19. Phonon Softening and Elastic Instabilities in the Cubic-to-Orthorhombic Structural Transition of CsH. https://doi.org/10.1103/physrevlett.78.4958

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