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Université de Fribourg

Calculation of spin-orbit coupling within the LFDFT: Applications to [NiX₄]²⁻ (X=F⁻, Cl⁻, Br⁻, I⁻)

Atanasov, Mihail ; Rauzy, Cédrick ; Baettig, Pio ; Daul, Claude A.

In: International Journal of Quantum Chemistry, 2005, vol. 102, p. 119-131

Spin-orbit coupling has been introduced into our newly developed ligand field density functional theory (LFDFT), using the zero-order regular approximation as implemented into the Amsterdam density functional (ADF) code. Application of the formalism to a series of NiX₄²⁻ (X=F⁻, Cl⁻, Br⁻, I⁻) compounds shows the increasing importance of intra-ligand spin-orbit coupling across the F,...

Université de Fribourg

Assessment of theoretical prediction of the NMR shielding tensor of ¹⁹⁵PtClxBr6–x²⁻ complexes by DFT calculations: experimental and computational results

Penka Fowe, Emmanuel ; Belser, Peter ; Daul, Claude A. ; Chermette, Henry

In: Physical Chemistry Chemical Physics, 2005, vol. 7(8), p. 1732-1738

In the present work, the ZORA spin–orbit Hamiltonian, in conjunction with the gauge including orbital (GIAO) method based on DFT theory has been used to calculate ¹⁹⁵Pt chemical shift of ¹⁹⁵PtClxBr6–x²⁻ complexes. Excellent agreement with experiments has been obtained for calculations bearing on optimized geometries and all electrons triple zeta +...

Université de Fribourg

Evaluation of two-electron integrals including the factors rk₁₂exp(−γr²₁₂) over Cartesian Gaussian functions

Weber, Valéry ; Daul, Claude A.

In: Computer Physics Communications, 2004, vol. 158 (1), p. 1-11

We present a practical scheme for the evaluation of nonstandard two-electron integrals including the factors rk₁₂exp(−γr²₁₂) which have been appeared recently, where k>=-1 is an integer. The method used throughout this paper is based on the highly efficient Head-Gordon and Pople (HGP) approach of evaluation of electron repulsion integrals (ERI). Thus only straightforward...

Université de Fribourg

Radial numerical integrations based on the sinc function

Weber, Valéry ; Daul, Claude A. ; Baltensperger, Richard

In: Computer Physics Communications, 2004, vol. 163(3), p. 133-142

An algorithm for the generation of adaptive radial grids used in density functional theory or quantum chemical calculations is described. Our approach is general and can be applied for the integration over Slater or Gaussian type functions with only minor modifications. The relative error of the integration is fully controlled by the algorithm within a specified range of exponential parameters...

Université de Fribourg

The calculation of ESR parameters by density functional theory: the g- and A-tensors of Co(acacen)

Atanasov, Mihail ; Baerends, Evert Jan ; Baettig, Pio ; Bruyndonckx, Raf ; Daul, Claude A. ; Rauzy, Cédrick ; Zbiri, Mohamed

In: Chemical Physics Letters, 2004, vol. 399(4-6), p. 433-439

The new DFT based ligand field (LF) model is proposed to calculate the g- and A-tensors of [Co(acacen)] that is known to be a difficult case. The results obtained are compared with the ZORA approach implemented in ADF as well as with the experimental values. The calculations are in good agreement with the experimental data and demonstrate the ability of the method to reproduce the large...

Université de Fribourg

FP-LAPW investigation of electronic structure of TaN and TaC compounds

Sahnoun, Mohammed ; Daul, Claude A. ; Driz, Mohamed ; Parlebas, J.C. ; Demangeat, C.

In: Computational Materials Science, 2005, vol. 33(1-3), p. 175-183

We study the structural and electronic properties of tantalum compounds, i.e. TaC and TaN, by means of accurate first principle total energy calculations using the full-potential linearized augmented plane wave plus local orbitals (FP-LAPW + lo) method. The calculations are based on density functional theory and we use the local density approximation (LDA) as well as the generalized gradient...

Université de Fribourg

Full potential calculation of structural, electronic and optical properties of KMgF₃

Sahnoun, Mohammed ; Zbiri, Mohamed ; Daul, Claude A. ; Khenata, R. ; Baltache, H. ; Driz, M.

In: Materials Chemistry and Physics, 2005, vol. 91(1), p. 185-191

A theoretical study of the structural, electronic and optical properties of KMgF₃ is presented using the full-potential linearized augmented plane wave method (FP-LAPW). In this approach, the local density approximation was used for the exchange-correlation potentials. First, we present the main features of the structural and electronic properties of this compound, where the electronic band...

Università della Svizzera italiana

Hedging and risk measurement for option portfolios

Fierli, Francesco ; Barone-Adesi, Giovanni (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2004 ; 2004ECO005.

In the first part of this work we address the problem of parameter misspecification in a generic class of stochastic volatility models. We extend the approach proposed by Avellaneda, Levy and Paràs (1995) (hereafter ALP) by moving from a framework with uncertain volatility to the uncertainty on volatility process parameters. We assume that parameter values of the stochastic volatility model are...

Université de Fribourg

Paléoécologie et paléoclimats de la molasse du Jura (oligo-miocène) : apport des Rhinocerotoidea (Mammalia) et des minéraux argileux

Becker, Damien ; Berger, Jean-Pierre (Dir.)

Thèse de doctorat : Université de Fribourg, 2003 ; no 1416.

Die Jura Molasse ist im distalen Tei des Molasse Beckens, einem klassischen Vorland-Becken, erhalten und überdeckte wärend des Oligo-Miozäns wahrscheinlich ein Grossteil der Jurakette. Heute findet man sie nur noch sporadisch in Talmulden oder als Karstfüllungen erhalten. Die Litho- und Biostratigraphie aller neogenen Jura-Ablagerungen sind Gegenstand einer Revision und einer Synthese. Jede...

Université de Fribourg

Intracellular vesicle transport in "Arabidopsis thaliana" : functional characterization of the t-SNARE homologue AtSNAP33

Wick, Peter ; Sticher, Liliane (Dir.)

Thèse de doctorat : Université de Fribourg, 2002 ; no 1386.

Alle eukaryontischen Zellen benötigen für die Sekretion ein funktionierendes endomembranes System. Proteine, die sekretiert werden besitzen ein Signalpeptid und werden am Endoplasmatischen Retikulum (ER) synthetisiert. Das Signalpeptid initiiert den Transport in den Lumen des ER und wird danach enzymatisch vom Protein abgetrennt. Korrekt gefaltete Proteine werden in Vesikel gepackt, die sich...