Nonmagnetic and ferromagnetic fcc cerium studied with one-electron methods

Article

关键词: LOCAL-DENSITY APPROXIMATION;    ALPHA-GAMMA TRANSITION;    MEAN-FIELD THEORY;    FUNCTIONAL THEORY;    EXACT EXCHANGE;    CE;    STATES;   

DOI  :  10.1103/PhysRevB.89.155106

来源: SCIE

【 摘 要 】

Density functional theory was used to study the nonmagnetic (NM) and ferromagnetic (FM) phases of face-centered cubic cerium. Functionals of four levels of approximation for the exchange-correlation energy were used: LDA, PBE, LDA/PBE + U, and YS-PBEh. The latter two contain an adjustable parameter, the onsite Coulomb repulsion parameter U for LDA/PBE + U, and the fraction alpha(x) of Hartree-Fock exchange for YS-PBEh, which were varied in order to study their influence on the results. By supposing that, as a first approximation, the NM and FM solutions can be identified to the observed alpha and gamma phases, respectively, it is concluded that while a small value of U or alpha(x) leads to the correct trend for the stability ordering of the two phases, larger values are necessary for a more appropriate (but still not satisfying) description of the electronic structure.

【 授权许可】

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