6533b85efe1ef96bd12c0683
RESEARCH PRODUCT
Semi-empirical Hartree-Fock calculations for KNbO 3 and KTaO 3
Roberts I. EglitisAndrei PostnikovG. Borstelsubject
Chemical speciesCondensed matter physicsPhononChemistryFormula unitAb initioHartree–Fock methodScale (descriptive set theory)Electronic structureAtomic physicsFerroelectricitydescription
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 SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1997-02-04 | SPIE Proceedings |