Hybrid density functional theory LCAO calculations of phonos in Ba (Ti, Zr, Hf)3
Название публикации:
Hybrid density functional theory LCAO calculations of phonos in Ba (Ti, Zr, Hf)3
Тип:
Публикация
Выходные данные публикации:
Physical Review B - condensed matter and materials physics, April 2011, -Vol. 83, -№1, -P. 014105
Дата публикации:
2011-01
Аннотация:
<p>Phonon frequencies at the Γ, X, M, and R points of the Brillouin zone (BZ) in the cubic phase of Ba(Ti,Zr,Hf)<sub>3</sub> were calculated by the frozen phonon method using density functional theory with the hybrid exchange correlation functional PBE0. The calculations use linear combination of atomic orbitals basis functions as implemented in the crystal09 computer code. The Powell algorithm was applied for basis-set optimization. In agreement with experimental observations, the structural instability via soft modes was found only in BaTiO<sub>3.</sub> A good quantitative agreement was found between the theoretical and experimental phonon frequency predictions in BaTiO<sub>3</sub> and BaZrO<sub>3</sub>. It is concluded that the hybrid PBE0 functional is able to predict correctly the structural stability and phonon properties in perovskites under consideration. The symmetry of phonons for nonzero k vector (X, M, and R points of the BZ) is given for each calculated phonon frequency, and it will be useful for future comparison of the calculated results with the experimental data on neutron scattering (such data are absent at present).</p>
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