Density Functional Theory; Ligand Field Theory; Single Molecular Magnets; Computational Quantum Chemistry; Vibronic coupling; Warm-white light
Amador Garcia-Fuente, Fanica Cimpoesu, Harry Ramanantoanina, Benjamin Herder, Claude Daul, Markus Suta, Claudia Wickleder, Werner Urland (2015), A ligand field theory-based methodology for the characterization of the Eu2+ [Xe]4f65d1 excited states in solde state compounds, in Chem. Phys. Lett.
, 622, 120.
Marko Perić Amador García-Fuente Matija Zlatar Prof. Claude Daul Stepan Stepanović Dr. Pablo Ga (2015), Magnetic Anisotropy in “Scorpionate” First-Row Transition-Metal Complexes: A Theoretical Investigation, in Chem. A Eur. J
, 21, 3716.
Benjamin Herdern, Amador Garcia-Fuente, Harry Ramanantoanina, Thomas Jüstel, Claude Daul, Werner Urland (2015), Photon cascade emission in Pr3+ doped fluoride with CaF2 structure: Application of a model for its prediction, in Chem. Phys. Lett.
, 620, 29.
Harry Ramanantoanina, Werner Urland, Benjamin Herden, Fanica Cimpoesu, Claude Daul (2015), Tailoring the optical properties of lanthanide phosphors: a prediction and characterization of the luminescence of Pr3+-doped LiYF4, in Phys. Chem. Chem. Phys
, 17, 9116.
Marko Perić, Ljubica Andjelković, Matija Zlatar, Claude Daul, Maja Gruden-Pavlović (2014), DFT investigation of the influence of Jahn–Teller distortion on the aromaticity in square-planar arsenic and antimony clusters, Polyhedron, in Polyhedron
, 80, 69.
Harry Ramanantoanina, Werner Urland, Amador Garcia-Fuente, Fanica Cimpoesu, Claude Daul (2014), Ligand Field Density Functional Theory for the prediction of future domestic lighting, in Phys. Chem. Chem. Phys.
, 16, 14625.
Claude Daul (2014), Non-empirical Prediction of the Photophysical and Magnetic Properties of Systems with Open d- and f-Shells Based on Combined Ligand Field and Density Functional Theory (LFDFT), in CHIMIA International Journal for Chemistry
, 68, 633.
Harry Ramanantoanina, Werner Urland, Fanica Cimpoesu, Claude Daul (2014), The Angular Overlap Model extended for two-open-shell f and d electrons, in Phys. Chem. Chem. Phys.
, 16, 12282.
Fanica Cimpoesu, Nita Dragoe, Harry Ramanantoanina, Werner Urland, Claude Daul (2014), The theoretical account of the ligand field bonding regime and magnetic anisotropy in the DySc2N@C80 single ion magnet endohedral fullerene, in Phys. Chem. Chem. Phys.
, 16, 11337.
Harry Ramanantoanina, Mohammed Sahnoun, Andrea Barbiero, Marilena Ferbinteanu, Fanica Cimpoesu, Development and applications of the LFDFT: the non-empirical account of ligand field and the simulation of the f–d transitions by density functional theory, in Phys. Chem. Chem. Phys.
Gregory Morrison, Harry Ramanantoanina, Werner Urland, Mark D. Smith, Hans-Conrad zur Loye, Flux Synthesis, Structure, Properties, and Theoretical Magnetic Study of Uranium(IV)-Containing A2USi6O15 (A = K, Rb) with an Intriguing Green-to-Purple, Crystal-to-Crystal Structural Transition in th, in Inorg. Chem.
, 54, 5504.
Fanica Cimpoesu, Bogdan Frescus, Cornellu I. Oprea, Harry Ramanantoanina, Werner Urland, Claude Daul, On exchange coupling and bonding in the Gd2@C80 and Gd2@C79N endohedral dimetallo-fullerenes, in Mol. Phys
Our research project will be composed of three different topics that are interrelated and cover a wide range of applications in molecular sciences. However, the common feature of all these mini-projects will be that the studied systems contain d- and/or f-elements, generally with open shells. Next, we give a short description of these three topics:a) The quest for phosphor that emit warm-white lightThis is a completely new field for us, but of outmost interest for the whole society. To achieve this goal we plan to use a Ligand Field Density Functional Theory (LFDFT) based methodology for the analysis of the 4fn ? 4fn-1 5d1 transitions in rare earth compounds and apply it, in a first step, for the characterization of the 4f2 ? 4f1 5d1 transitions in the quantum cutter Cs2KYF6: Pr3+ with the elpasolite structure type. The positions of the zero-phonon energy corresponding to the states of the electron configurations 4f2 and 4f1 5d1 are calculated, where the praseodymium ion may occupy either the Cs+-, K+- or Y3+-site, and are compared with available experimental data. The theoretical results show that the occupation of the three undistorted sites allows a quantum-cutting process. However size effects due to the difference between the ionic radii of Pr3+ and Cs+ as well as K+ lead to the distortion of the Cs+- and K+- sites, which finally exclude these sites for quantum-cutting. b) Development and validation of DFT-based model to describe accurately the pseudo-Jahn-Teller effect in molecular systemsBased on the pseudo Jahn-Teller effect (PJTE) theory, an approach is developed to rationalize and predict the conformations and conformational changes in molecular systems with a common pattern, i.e. the presence of two or more states amongst the frontier orbitals that belong to the same irrep GPJTE. It is shown that starting with the high-symmetry (hs) geometry of the environment, the set of GPJTE orbitals descends from (hs) to low-symmetry (ls) which produces a variety of PJT distortions. Further PJT interactions with higher energy degenerate states may trigger additional distortions which in (ls) are classified as Gls. The realization of these conformations depends on the positions of the excited GPJTE-states and the PJTE parameter values. The emerging PJTE-problems, are formulated in the matrix form and provide a general picture of the ground and excited adiabatic potential energy surfaces. Following this scheme in combination with Multi-Determinant calculations, the possible conformations and conformational transitions are analyzed for several specific systems. c) Non-empirical prediction of molecular magnetism: In this third topic, we adress some basic aspects concerning the magnetic properties of transition metal and rare-earth ions, which are currently the subject of a renovated interest in the field of molecular magnetism, after the discovery that slow relaxation of the magnetization at liquid nitrogen temperature can occur in mononuclear complexes of these ions. Focusing on Ln(III) derivatives we will stress the relation of the crystal field parameters, which determine the anisotropy of these systems and consequently their interesting magnetic properties, with the geometry of the coordination sphere around the lanthanide centre and with the pattern of f orbitals. The problem of systems of low point symmetry is also addressed by studying how detailed single crystal investigation, coupled to more sophisticated calculation procedures, is an absolute necessity to obtain meaningful structure-property relationships in these systems.