Ab initio derivation of the low-energy model for alkali-cluster-loaded sodalites

Article

关键词: MEAN-FIELD THEORY;    ELECTRONIC-STRUCTURE CALCULATIONS;    DENSITY-FUNCTIONAL APPROACH;    BAND-STRUCTURE CALCULATIONS;    QUASI-PARTICLE ENERGIES;    INTRACAVITY ELECTRONS;    CORRELATED SYSTEMS;    WANNIER FUNCTIONS;    SELF-INTERACTION;    ZEOLITE LTA;   

DOI  :  10.1103/PhysRevB.80.174420

来源: SCIE

【 摘 要 】

An effective low-energy model describing magnetic properties of alkali-cluster-loaded sodalites is derived by ab initio downfolding. We start with constructing an extended Hubbard model for maximally localized Wannier functions. Ab initio screened Coulomb and exchange interactions are calculated by constrained random-phase approximation. We find that the system resides in the strong-coupling regime and thus the Heisenberg model is derived as a low-energy model of the extended Hubbard model. We obtain antiferromagnetic couplings similar to O(10 K), being consistent with the experimental temperature dependence of the spin susceptibility. Importance of considering the screening effect in the derivation of the extended Hubbard model is discussed.

【 授权许可】

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