Université de Fribourg

Modeling the properties of open d-shell molecules with a multi-determinantal DFT

Rauzy, Cédrick ; Daul, Claude (Dir.)

Thèse de doctorat : Université de Fribourg, 2005 ; Nr. 1465.

La théorie du champ des ligands a été utilisée avec succès durant des décennies pour décrire l’état fondamental et les états excités des complexes. Les chimistes utilisent cette théorie afin d’interpréter des spectres UV-Vis essentiellement. D’un autre côté, les chimistes computationels peuvent décrire assez précisément les propriétés correspondant à l’état...

Université de Fribourg

Polytopal rearrangement of [Ni(acac)₂(py)]: A new square pyramid ⇄ trigonal bipyramid twist mechanism

Daul, Claude ; Niketic, Svetozar ; Rauzy, Cédrick ; Schläpfer, Carl-Wilhelm

In: Chemistry - A European Journal, 2004, vol. 10(3), p. 721-727

The interconversion mechanisms between three idealized polytopal forms (a square pyramid and two trigonal bipyramids) of [M(bidentate)₂(unidentate)] were investigated by an original combination of molecular mechanics (MM) and density functional theory (DFT) approaches. MM was used to model the mechanistic rearrangement path, and DFT to study selected points along this path. The test case was a...

Université de Fribourg

DFT study of mixed-valent Mn(II/III) hexacyanide clusters

Daul, Claude ; Rauzy, Cédrick ; Decurtins, Silvio ; Franz, Patrick ; Hauser, Andreas

In: International Journal of Quantum Chemistry, 2005, vol. 101 (6), p. 753-760

The cubic Prussian blue analogue Mn³[Mn(CN)₆]₂·15H₂O, which has the advantage of being transparent and magnetic (TN = 35 K) at the same time, has been investigated by density functional theory (DFT) calculations. The three-dimensional structure is built of MnII ions linked to MnIII ions by μ-bridging cyanides, to form a crystal structure,...

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

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...