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Proceedings Paper

Semi-empirical Hartree-Fock calculations for KNbO3 and KTaO3
Author(s): R. I. Eglitis; A. V. Postnikov; G. Borstel
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Paper 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.

Paper Details

Date Published: 4 February 1997
PDF: 6 pages
Proc. SPIE 2967, Optical Inorganic Dielectric Materials and Devices, (4 February 1997); doi: 10.1117/12.266525
Show Author Affiliations
R. I. Eglitis, Univ. of Latvia and Univ. Osnabrueck (Latvia)
A. V. Postnikov, Univ. Osnabrueck (Germany)
G. Borstel, Univ. Osnabrueck (Germany)


Published in SPIE Proceedings Vol. 2967:
Optical Inorganic Dielectric Materials and Devices
Andris Krumins; Donats K. Millers; Andris R. Sternberg; Janis Spigulis, Editor(s)

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