AB Initio Approach to the Ferroelectric Properties of ABO 3 Perovskites: The Case of KNbO 3
Autor: | Ph. Baranek, Roberto Dovesi |
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Rok vydání: | 2002 |
Předmět: |
Wannier function
Materials science Condensed matter physics Hartree–Fock method Ab initio Condensed Matter Physics Electronic Optical and Magnetic Materials Condensed Matter::Materials Science Delocalized electron Ab initio quantum chemistry methods Physics::Atomic and Molecular Clusters Physics::Chemical Physics Local-density approximation Ground state Basis set |
Zdroj: | Ferroelectrics. 268:155-162 |
ISSN: | 1563-5112 0015-0193 |
DOI: | 10.1080/00150190211078 |
Popis: | The ferroelectric perovskite KNbO 3 is investigated at the ab initio quantum mechanical level, by using the CRYSTAL program and a gaussian type basis set. A set of well localized Wannier functions (LWF) is obtained by applying a unitary transformation to the delocalized crystalline orbitals describing the ground state. The spontaneous polarization, the Born effective charges and the piezo-electric constants obtained from the LWF with various hamiltonians are compared. The calculations are performed at the Hartree-Fock (HF), density functional (DFT) and hybrid (B3LYP) level of theory. As regards DFT, the local density (LDA) and generalized gradient (GGA) approximations are used. |
Databáze: | OpenAIRE |
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