In: Tetrahedron, 2006, vol. 62, no. 48, p. 11106-11111
A new 1,3-dithiol-2-ylidene substituted naphthopyranone 2 has been synthesized and characterized. UV–vis spectroscopic and cyclic voltammetry results, interpreted on the basis of density functional theory, show that 2 displays an intramolecular charge-transfer transition and acts like a donor–acceptor (D–A) system. Furthermore, a weak fluorescence originating from the excited...
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In: Chemical Physics Letters, 2006, vol. 427, no. 4-6, p. 449-454
Using a DFT based Ligand Field treatment (LFDFT) of the electronic structure of Co(II) and Cu(II) porphyrins (CoP and CuP) we analyse the origin of their EPR spectra. From a comparison between theoretical result on Co model clusters (CoP and CoP–ZnP dimer) we conclude that the g-tensor values are very sensitive to the axial coordination which stabilizes a ²A₁ ground state in good...
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In: Chimia, 2006, vol. 60, no. 4, p. 228-230
Energetics and the electronic structure of various types of single-walled carbon nanotubes have been investigated by using Density Functional Theory. Armchair [n,n], zigzag [n,0] and chiral [n,m] C₄₀H₂₀ nanotubes have been considered. Calculations show that the armchair isomer is the most stable among the three types and they further reveal the factors that stabilize this isomer....
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In: Comptes Rendus Chimie, 2006, vol. 9, no. 2, p. 226-239
Nous rendons compte ici des performances d'une approche moderne et opérante de la théorie de la fonctionnelle de la densité (DFT) pour la prédiction du comportement photophysique de composés du ruthénium (II) et de l'osmium(II). Pour interpréter leurs propriétés d'absorption électronique, l'approche DFT dépendante du temps a été utilisée. Nous illustrons notre propos par l'analyse...
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In: Journal of Molecular Structure: THEOCHEM, 2006, vol. 762, no. 1-3, p. 93-10
In this work we apply in a systematic way our multi-determinantal model to calculate the fine structure of the whole atomic multiplet manifold. The key feature of this approach is the explicit treatment of near-degeneracy correlation using ad hoc configuration interaction (CI) within the active space of Kohn–Sham (KS) orbitals with open d- or f-shells. The calculation of the CI-matrices is...
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In: The Journal of Chemical Physics, 2006, vol. 124, p. 214105
Recently, linear scaling construction of the periodic exact Hartree-Fock exchange matrix within the Γ-point approximation has been introduced [J. Chem. Phys. 122, 124105 (2005)]. In this article, a formalism for evaluation of analytical Hartree-Fock exchange energy gradients with respect to atomic positions and cell parameters at the Γ-point approximation is presented. While the...
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In: Journal of Chemical Theory and Computation, 2006, vol. 2, no. 4, p. 1106-1111
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In: Journal of Physics: Condensed Matter, 2006, vol. 17, p. 7995-8003
The electronic and magnetic properties of both LaCoO₃ and La0.5Ca0.5CoO₃ have been investigated by means of ab initio full-potential augmented plane wave plus local orbitals (APW+lo) calculations carried out with the Wien 2k code. The functional used is the local-density approximation LDA +U. Doping with Ca²⁺ introduces holes into the Co–O...
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In: The European Physical Journal B, 2005, vol. 45, no. 4, p. 455-458
We present first-principles calculations for the optical properties of germanium dioxide in the rutile structure. The electronic band structure has been calculated self-consistently within the local density approximation using the full-potential linearized augmented plane wave method. The electronic band structure shows that the fundamental energy gap is direct at the center of the Brillouin...
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In: The European Physical Journal B, 2005, vol. 44, no. 3, p. 281-286
The electronic and optical properties of tantalum carbide TaC have been calculated using the full-potential linearized augmented-plane-wave method within the local density approximation scheme for the exchange-correlation potential. We find that the optical spectra can be extremely sensitive to the Brillouin zone sampling. The influence of relativistic effects on the dielectric function is...
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