Franck Rabilloud - Academia.edu (original) (raw)

Papers by Franck Rabilloud

Journal of Physical Chemistry C, Jan 15, 2019

International Journal of Quantum Chemistry, Jul 3, 2023

Journal of Chemical Physics, Nov 15, 1999

Ab initio configuration interaction ͑CI͒ calculations are performed to study the ground state of ... more Ab initio configuration interaction ͑CI͒ calculations are performed to study the ground state of small neutral and singly charged silver bromide clusters Ag n Br p (Ϯ) (n,pр2). The results are obtained at complete active space self-consistent field and also at variational plus second order perturbational multireference CI ͑MRPT2͒ levels of approximation. We discuss more particulary the structural properties and the stability of the lowest isomers. Adiabatic and vertical ionization potentials and electron affinities have also been determined.

Journal of Molecular Modeling, Apr 5, 2019

The structural, electronic and magnetic properties of niobium and tantalum doped germanium cluste... more The structural, electronic and magnetic properties of niobium and tantalum doped germanium clusters MGen (M = Nb, Ta and n = 1-19) are investigated by first principles calculations within the Density Functional Theory approach (DFT). The growth pattern behaviors, stabilities, and electronic properties are presented and discussed. Endohedral cagelike structures in which the metal atom is encapsulated are favored for n ≥ 10. The doping metal atom contributes largely to strengthen the stability of the germanium cage-like structures with the binding energy ordered as follows BE(Gen+1) < BE (VGen) < BE(NbGen) < BE(TaGen). Our results highlight the relative high stability of NbGe15, TaGe15 and VGe14.

Journal of Physical Chemistry A, Jul 19, 2007

Low-lying equilibrium geometric structures of Al n N (n ϭ 1-12) clusters obtained by an all-elect... more Low-lying equilibrium geometric structures of Al n N (n ϭ 1-12) clusters obtained by an all-electron linear combination of atomic orbital approach, within spinpolarized density functional theory, are reported. The binding energy, dissociation energy, and stability of these clusters are studied within the local spin density approximation (LSDA) and the three-parameter hybrid generalized gradient approximation (GGA) due to Becke-Lee-Yang-Parr (B3LYP). Ionization potentials, electron affinities, hardness, and static dipole polarizabilities are calculated for the ground-state structures within the GGA. It is observed that symmetric structures with the nitrogen atom occupying the internal position are lowest-energy geometries. Generalized gradient approximation extends bond lengths as compared with the LSDA lengths. The odd-even oscillations in the dissociation energy, the second differences in energy, the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps, the ionization potential, the electron affinity, and the hardness are more pronounced within the GGA. The stability analysis based on the energies clearly shows the Al 7 N cluster to be endowed with special stability.

Physical Chemistry Chemical Physics, 2010

The structural, electronic, magnetic and optical properties of protactinium oxides (PaO and PaO 2... more The structural, electronic, magnetic and optical properties of protactinium oxides (PaO and PaO 2) have been studied within the framework of all-electron full potential linear augmented plane wave method of density functional theory. We apply the local spin density approximation/Perdew-Burke-Ernzerhof generalized gradient approximation (LSDA/PBE) ? U with spin-orbit coupling (SOC) formalism to these compounds and compare them with the calculations of Obodo et al. (J Phys Condens Matter 25: 145603, 2013). Whereas a good agreement is obtained for PaO, our PBE and PBE ? U (SOC) results differ from this study in the case antiferromagnetic (AFM) of PaO 2. By choosing the Hubbard U parameter around 4.0 eV, 1.42 eV band gap for PaO 2 is in good agreement with Prodan et al. (Phys. Rev. B 76: 033101, 2007). In particular, our simulations performed at PBE ? U and PBE ? U (SOC) levels both describe an increase in the band gap for PaO 2 when increasing U. Finally, the frequency-dependent dielectric functions and optical properties of PaO 2 are performed.

HAL (Le Centre pour la Communication Scientifique Directe), 2012

Understanding the charging kinetics of electric double layers is of fundamental importance for th... more Understanding the charging kinetics of electric double layers is of fundamental importance for the design and development of novel electrochemical devices such as supercapacitors and field-effect transistors. In this work, we study the dynamic behavior of room-temperature ionic liquids using a classical time-dependent density functional theory that accounts for the molecular excluded volume effects, the electrostatic correlations, and the dispersion forces. While the conventional models predict a monotonic increase of the surface charge with time upon application of an electrode voltage, our results show that dispersion between ions results in a non-monotonic increase of the surface charge with the duration of charging. Furthermore, we investigate the effects of van der Waals attraction between electrode/ionic-liquid interactions on the charging processes.

Computational and Theoretical Chemistry, Dec 1, 2017

Density functional theory calculations have been performed to study the geometrical structures, r... more Density functional theory calculations have been performed to study the geometrical structures, relative stabilities, electronic and magnetic properties of Pn+1 and FePn clusters in the range of n = 1 to 14 atoms. The search of the lowest-energy isomers has been performed by considering lots of structures for each clusters sizes. The putative geometries show that the frameworks of the lowest-energy isomers are three-dimensional structures and Fe atom tends to be located at an endohedral position from size n = 7. The growth pattern behaviors and relative stabilities are analyzed from the binding energies, second-order difference of energies, and HOMO-LUMO energy gaps. Doping with Fe atom enhances the stability of the Pn clusters. The HOMO-LUMO gaps are significantly affected after the introducing of a Fe atom into a phosphorus cluster. The vertical ionization potential (VIP), vertical electron affinity (VEA) and chemical hardness (η) are also calculated and discussed. The total spin magnetic moment analyses show that Fe atom can enhance dramatically the magnetic moment of the host cluster, but in some cases the magnetic moment is fully quenched. The total and partial density of states of clusters are discussed to understand the origin of these peculiar magnetic properties.

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The Journal of Chemical Physics, 2020

Dissociative electron attachment is a mechanism found in a large area of research and modern appl... more Dissociative electron attachment is a mechanism found in a large area of research and modern applications. This process is initiated by a resonant capture of a scattered electron to form a transitory anion via the shape or the core-excited resonance that usually lies at energies above the former (i.e., >3 eV). By studying experimentally and theoretically the interaction of nickel(II) (bis)acetylacetonate, Ni(II)(acac)2, with low energy electrons, we show that core-excited resonances are responsible for the molecular dissociation at unusually low electron energies, i.e., below 3 eV. These findings may contribute to a better description of the collision of low energy electrons with large molecular systems.

Journal of Molecular Structure, 2017

New tetradentate mononuclear nickel(II) [NiL] and pentadentate binuclear copper(II) [Cu 2 L 2 H 2... more New tetradentate mononuclear nickel(II) [NiL] and pentadentate binuclear copper(II) [Cu 2 L 2 H 2 O], H 2 O Schiff base complexes have been synthesized. The crystal structures of [NiL] and [Cu 2 L 2 H 2 O], H 2 O have been determined by X-ray diffraction method showing distorted squareplanar geometry for [NiL] and distorted tetragonal pyramid geometry for [Cu 2 L 2 H 2 O], H 2 O. In both complexes, the dehydroacetic acid functional group engages in a deprotonated manner and coordination occurs through the nitrogen atoms of the imine function and the phenolic oxygen. Density Functional Theory calculations are carried out for the determination of the optimized structures. The fundamental vibrational wave numbers are calculated and a good agreement between observed and calculated wave numbers is achieved.

Inorganic Chemistry, Apr 29, 2022

Amine ligands are expected to drive the organization of the metallic centers as well as the chemi... more Amine ligands are expected to drive the organization of the metallic centers as well as the chemical reactivity of the silver clusters early growing during the very first steps of the synthesis of silver nanoparticles via an organometallic route. DFT (Density Functional Theory) computational studies have been performed in order to characterize the structure, the atomic charge distribution and the planar (2D)/three-dimensional (3D) relative stability of small-size silver clusters (, 2 ≤ n ≤ 7), with or without an ethylamine (EA) ligand coordinated to the Ag clusters. The transition from 2D to 3D structures is shifted from n = 7 to n = 6 in the presence of one EA coordinating ligand and it is explained from the analysis of the Ag-N and Ag-Ag bond energies. For fully EA saturated silver clusters (−) the effect on the 2D/3D transition is even more pronounced with a shift between n = 4 and n = 5. Subsequent ELF (Electron Localization Function) and QTAIM (Quantum Theory Atoms in Molecules) topological analyses allow for the fine characterization of the dative Ag-N and metallic Ag-Ag bonds, both in nature and strength. Electron transfer from the ethylamine to the coordinated silver atoms induces an increase of the polarization of the metallic core.

Journal of Chemical Theory and Computation

Journal of Nanoparticle Research, 2021

First principles calculations are performed to investigate the structural and electronic properti... more First principles calculations are performed to investigate the structural and electronic properties of small IrGe n (n = 1-20) clusters. Cage-like configurations where the iridium atom is encapsulated inside a germanium cage are predicted to be favored for n ≥ 12. Doping Ir atom enhances the stability of the corresponding germanium frame. Our results highlight the great stability of IrGe 13 which presents a high-symmetry cage-like geometry and a peculiar electronic structure in which the valence electrons of Ir and Ge atoms are delocalized and exhibit a shell structure. Absorption spectra, vertical ionization potentials, and electron affinities are also calculated and discussed.

The Journal of Physical Chemistry A, 2018

Structures, energetics and electronic properties of noble metal-doped germanium (MGen with M = Cu... more Structures, energetics and electronic properties of noble metal-doped germanium (MGen with M = Cu, Ag, Au; n=1-19) clusters are systematically investigated by using the density-functional theory (DFT) approach. The endohedral structures in which the metal atom is encapsulated inside a germanium cage appear at n = 10 when the dopant is Cu, and n = 12 for M = Ag and Au. While Cu doping enhances the stability of the corresponding germanium frame, the binding energies of AgGen and AuGen are always lower than those of pure germanium clusters. Our results highlight the great stability of the CuGe10 cluster in a D4d structure, and to a lesser extent that of AgGe15 and AuGe15 which exhibits a hollow cage-like geometry. The sphere-type geometries obtained for n = 10-15 present a peculiar electronic structure in which the valence electrons of the noble metal and Ge atoms are delocalized and exhibit a shell structure associated with the quasi-spherical geometry. It is found that the coinage metal is able to give both sand d-type electrons to be reorganized together with the valence electrons of Ge atoms through a pooling of electrons. The cluster size dependence of the stability, the frontier orbital energy gap, the vertical ionization potentials, and electron affinities are given.

International Journal of Molecular Sciences, 2021

In this contribution the dissociative electron attachment to metabolites found in aerobic organis... more In this contribution the dissociative electron attachment to metabolites found in aerobic organisms, namely oxaloacetic and citric acids, was studied both experimentally by means of a crossed-beam setup and theoretically through density functional theory calculations. Prominent negative ion resonances from both compounds are observed peaking below 0.5 eV resulting in intense formation of fragment anions associated with a decomposition of the carboxyl groups. In addition, resonances at higher energies (3–9 eV) are observed exclusively from the decomposition of the oxaloacetic acid. These fragments are generated with considerably smaller intensities. The striking findings of our calculations indicate the different mechanism by which the near 0 eV electron is trapped by the precursor molecule to form the transitory negative ion prior to dissociation. For the oxaloacetic acid, the transitory anion arises from the capture of the electron directly into some valence states, while, for the ...

Gold-containing compounds offer many applications in nanoscale materials science, and electron-be... more Gold-containing compounds offer many applications in nanoscale materials science, and electron-beam methods are versatile for shaping nanostructures. In this study, we report the energy-selective fragmentation of chloro(dimethyl sulfide)gold(I) (ClAuS(CH3)2) induced by slow electrons. We observe the resonant formation of four fragment anions, namely [Cl]-, [S]-, [CH2S]-, and [ClAuH···SH]-, which are generated in the energy range of 0-9 eV. The predominant fragment anion is formed below 1 eV from the cleavage of a single Au-Cl bond to produce the [Cl]- anion. The resonant states and the energetics of the fragmentation are investigated by DFT methods. These findings may contribute to future strategies in the elaboration of specific nanomaterials or for selective chemistry using electron-beam techniques.

ACS Photonics, 2017

Applications of noble metal clusters and nanoparticles in different size ranges abound-from a cou... more Applications of noble metal clusters and nanoparticles in different size ranges abound-from a couple of atoms through mesoscopic sizes. Classical electromagnetics calculations are now employed on smaller and smaller sizes, creating a effervescent dynamic in fields like plasmonics and approaching the tiny sizes where quantum effects and the atomistic structure of matter play predominant roles. Nonetheless, explicit demonstrations of their merits and limitations are rare. Here we study the optical absorption of sub-nanometric elongated coinage-metal particles using ab initio and classical electromagnetics methods. The comparison between both approaches reveals that the classical plasmonic frequencies are in astonishing agreement with those predicted by 1 ab initio theory for atomistic three-dimensional rods and quasi one-dimensional chains, as long as collective surface-plasmon resonances lie far below the onset of d-electron excitations. The physical origin of this striking agreement is clarified through the analysis of the resonant induced electron densities and with the aid of model calculations for a purely one-dimensional system of electrons. Furthermore, we show that even when plasmonic/collective and electron-hole excitations are strongly coupled, the classical description accounts rather well for the spectral average of the corresponding quantum hybrid excitations. Our theoretical findings demonstrate that classical optics is surprisingly accurate in describing localized surface plasmon resonances even for angstrom-sized systems, provided the geometrical modelling of the atomistic structures is properly defined.