Paper
4 February 1997 Semi-empirical Hartree-Fock calculations for KNbO3 and KTaO3
R. I. Eglitis, A. V. Postnikov, G. Borstel
Author Affiliations +
Proceedings Volume 2967, Optical Inorganic Dielectric Materials and Devices; (1997) https://doi.org/10.1117/12.266525
Event: International Conference on Advanced Optical Materials and Devices, 1996, Riga, Latvia
Abstract
As a first step in modeling the electronic structure of Perovskite-type ferroelectric mixed crystals K(Nb,Ta)O3, semiempirical calculations for pure KNbO3 and KTaO3 are performed with the intermediate neglect of the differential overlap (INDO) quantum chemical method. The calculations are mostly done for 40-atom supercells. The choice of the INDO parameters based on the comparison of results with ab initio and experimental data is discussed. INDO results for the equilibrium geometry and the (Gamma) -TO phonon frequencies are given. The results show that the accuracy of the INDO method is sufficient for reliably reproducing the energy differences on the order of 1 mRy (per formula unit) scale which are typical when dealing with ferroelectric instabilities.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
R. I. Eglitis, A. V. Postnikov, and G. Borstel "Semi-empirical Hartree-Fock calculations for KNbO3 and KTaO3", Proc. SPIE 2967, Optical Inorganic Dielectric Materials and Devices, (4 February 1997); https://doi.org/10.1117/12.266525
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KEYWORDS
Niobium

Chemical species

Phonons

Tantalum

Adaptive optics

Perovskite

Chemical elements

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