G. Borstel

Defects and surface-induced effects in advanced perovskites

Preface. List of Participants. I. Modelling of Defects and Surfaces. II. Experimental Study of Structure and Basic Properties HTSC. III. Effects on Surfaces, Interfaces and Thin Films. IV. Defects and Phase Transitions. V. Advanced Technologies, New Perovskite Materials and Applications. Author Index. Subject Index.

First-principles calculations for SrTiO3(100) surface structure

As a continuation of our recent abinitio calculations of SrTiO 3(1 0 0) surface relaxation for the two different terminations (SrO and TiO2) [Phys. Rev. B 64 (2001) 23417], we analyze here their electronic structures (band structure, density of states, and the electronic density redistribution with emphasis on the covalency effects). We compare results of abinitio Hartree–Fock method with electron correlation corrections and density functional theory with different exchange-correlation functionals, including hybrid (B3PW, B3LYP) exchange techniques. Our results are also compared with previous abinitio plane-wave local density approximation calculations and experiments when availab le. Considerable increase of Ti–O chemical bond covalency nearby the surface and the gap reduction, especially for the TiO2 termination, are confirmed. 2002 Elsevier Science B.V. All rights reserved.

FIRST-PRINCIPLES AND SEMIEMPIRICAL CALCULATIONS FOR BOUND-HOLE POLARONS INKNBO3

The ab initio linear muffin-tin-orbital formalism and the semiempirical method of the intermediate neglect of the differential overlap based on the Hartree-Fock formalism are combined for the study of the hole polarons ~a hole trapped nearby the cation vacancy! in a cubic phase of KNbO3 perovskite crystals. The 40-atom and 320-atom supercells were used, respectively. We predict the existence of both one-site and two-site ~molecular! polarons with close optical absorption energies ~0.9 eV and 0.95 eV!. The relevant experimental data are discussed. @S0163-1829~99!12725-5#

ONSET OF MAGNETISM IN B2 TRANSITION-METAL ALUMINIDES

Ab initio calculation results for the electronic structure of disordered bcc Fe(x)Al(1-x) (0.4 0.5.

FIRST-PRINCIPLES AND SEMIEMPIRICAL CALCULATIONS FOR F CENTERS IN KNBO3

The linear muffin-tin-orbital method combined with density functional theory (local approximation) and the semiempirical method of the intermediate neglect of the differential overlap (INDO) based on the Hartree-Fock formalism are used for the study of the

Semiempirical Hartree-Fock calculations for pure and Li-doped KTaO3

F

Semiempirical Hartree-Fock calculations for KNbO3

centers (O vacancy with two electrons) in cubic and orthorhombic ferroelectric KNbO

Ab initio calculations of the BaF2 bulk and surface F centres

_3

Quantum chemical modelling of electron polarons and charge-transfer vibronic excitons in BaTiO3 perovskite crystals

crystals. Calculations for 39-atom supercells show that the two electrons are considerably delocalized even in the ground state of the defect. Their wave functions extend over the two Nb atoms closest to the O vacancy and over other nearby atoms. Thus, the

Semi-empirical calculations of the electronic and atomic structure of polarons and excitons in ABO3 perovskite crystals

F