Comment on "On the importance of the free energy for elasticity under pressure"

Abstract

Marcus et al. (Marcus P, Ma H and Qiu S L 2002 J. Phys.: Condens. Matter 14 L525) claim that thermodynamic properties of materials under pressure must be computed using the Gibbs free energy $G$, rather than the internal energy $E$. Marcus et al. state that ``The minima of $G$, but not of $E$, give the equilibrium structure; the second derivatives of $G$, but not of $E$, with respect to strains at the equilibrium structure give the equilibrium elastic constants.'' Both statements are incorrect.

arXiv commentComment

References in corpus (2)

• First-Principles Elastic Constants for the hcp Transition Metals Fe, Co, and Re at High Pressure
• High Pressure Thermoelasticity of Body-centered Cubic Tantalum

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• Neutron star crust in Voigt approximation: general symmetry of the stress-strain tensor and an universal estimate for the effective shear modulus
• Neutron star crust in Voigt approximation II: general formula for electron screening correction for effective shear modulus