Density-functional Theory for f-electron Systems: the α-γ Phase Transition in Cerium

Physical Review Letters 109, 146402 (2012)

Density-functional Theory for f-electron Systems: the α-γ Phase Transition in Cerium

M. Casadei, X. Ren, P. Rinke, A. Rubio, M. Scheffler

The iso-structural α-γ phase transition in cerium is analyzed using density-functional theory with different exchange-correlation functionals, in particular the PBE0 hybrid functional and the exact- exchange plus correlation in the random-phase approximation ((EX+cRPA)@PBE0) approach. We show that the Hartree-Fock exchange part of the hybrid functional actuates two distinct solutions at zero temperature that can be associated with the α and γ phases of cerium. However, despite the relatively good structural and magnetic properties, PBE0 predicts the γ phase to be the stable phase at ambient pressure and zero temperature, in contradiction with low temperature experiments. EX+cRPA reverses the energetic ordering, which emphasizes the importance of correlation for rare- earth systems.

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http://dx.doi.org/10.1103/PhysRevLett.109.146402

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