Search results for " Functional"

showing 10 items of 1811 documents

The Role of the Anchor Atom in the Ligand of the Monolayer-Protected Au25(XR)18– Nanocluster

2015

We present a density functional theory (DFT) investigation on the role of the anchor atom and ligand on the structural, electronic, and optical properties of the anionic Au25(XR)18– nanocluster (X = S, Se, Te; R = H, CH3, and (CH2)2Ph). Substituting the anchor atom with other group 16 elements induces subtle changes in the Au–Au and Au–X bond lengths and polarization of the covalent bond. The changes in the electronic structure based on substituting both the anchor and R groups are presented through careful analysis of the density of states and theoretical determined optical spectra. We give a detailed side-by-side comparison into the structural, electronic, and optical properties of Au25(X…

ta114LigandChemistryligandsElectronic structureanchor atomsSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsBond lengthCrystallographyGeneral EnergyCovalent bondComputational chemistryAtomMonolayerDensity of statesDensity functional theoryPhysical and Theoretical Chemistryta116gold nanoclustersJournal of Physical Chemistry C
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The electronic structure of Ge9[Si(SiMe3)3]3-: a superantiatom complex.

2012

We report on the electronic structure of Ge(9)[Si(SiMe(3))(3)](3)(-). Systematic density functional theory analysis of the electronic shell structure of the cluster and its derivatives reveals that the Ge(9)[Si(SiMe(3))(3)](3)(-) and its neutral counterpart have electronic shells that can be explained using the superatom model. The ligand-core interaction of these complexes is distinctly different from previously identified gold, gallium, and aluminium superatom complexes, indicating an electron-donating rather than electron-withdrawing ligand. We modify the electron-counting rule for this case and introduce a simple picture for superatom and superantiatom complexes. Discussions comparing s…

ta114LigandSuperatomShell (structure)General Physics and Astronomychemistry.chemical_elementElectronic structurechemistryChemical physicsAluminiumCluster (physics)Density functional theoryPhysical and Theoretical ChemistryGalliumAtomic physicsPhysical chemistry chemical physics : PCCP
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Crystal Structures and Density Functional Theory Calculations of o-and p-Nitroaniline Derivatives: Combined Effect of Hydrogen Bonding and aromatic i…

2013

The interplay of strong and weak hydrogen bonds, dipole–dipole interactions, and aromatic interactions of o- and p-nitroaniline derivatives was studied by combining crystal structure analysis and density functional theory (DFT) calculations. Crystal structures of four 2-nitroaniline derivatives, 2-((2-nitrophenyl)amino)ethyl methanesulfonate (1A), 2-((2-nitrophenyl)amino)ethyl 4-methylbenzenesulfonate (2A), N,N′-((1,3-phenylenebis(oxy))bis(ethane-2,1-diyl))bis(2-nitroaniline) (3A), and N-(2-chloroethyl)-2-nitroaniline (4A), and crystal structures of three 4-nitroaniline derivatives, 2-((4-nitrophenyl)amino)ethyl methanesulfonate (1B), 2-((4-nitrophenyl)amino)ethyl 4-methylbenzenesulfonate (…

ta214Ethyl methanesulfonateta114Hydrogen bondIntermolecular forceAromaticityGeneral ChemistryCrystal structureCondensed Matter PhysicsRing (chemistry)Nitroanilinechemistry.chemical_compoundCrystallographychemistryComputational chemistryGeneral Materials ScienceDensity functional theoryta116Crystal Growth and Design
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Trans-cranial MRI-guided Focused Ultrasound Surgery (tcMRgFUS): preliminary Italian (and world-first) experience at 1,5 Tesla (first 5 patient treate…

2015

tcMRgFUS functional neurosurgery 1.5T MRISettore MED/27 - NeurochirurgiaSettore MED/37 - NeuroradiologiaSettore MED/36 - Diagnostica Per Immagini E Radioterapia
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Trans-cranial MRI-guided Focused Ultrasound Surgery (tcMRgFUS): preliminary Italian (and world-first) experience at 1,5 Tesla.

2015

PURPOSE: We present our preliminary results achieved with the first Italian installation of a trans-cranial MRI-guided Focused Ultrasound Surgery (tcMRgFUS) certified system for functional neurosurgery. Moreover, to our knowledge, this is the world-first tcMRgFUS system ever installed on a 1.5T MRI unit. Technical issues faced to achieve a safe and effective treatment will be discussed focusing on MR high-resolution live imaging and thermometry sequences optimization. METHOD AND MATERIALS: Patient enrollment was based on indication for functional neurosurgery and evidence of medication-refractory disease; a detailed medical history has been collected together with a complete clinical examin…

tcMRgFUS functional neurosurgery 1.5TSettore MED/27 - NeurochirurgiaSettore MED/37 - Neuroradiologia
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POST-THALAMOTOMY NEUROFUNCTIONAL FINDINGS ON PATIENTS TREATED WITH TRANS-CRANIAL MAGNETIC RESONANCE GUIDED FOCUSED ULTRASOUND SURGERY (TCMRGFUS): PRE…

2015

BACKGROUND AND PURPOSE: We present functional connectivity (FC) changes found in the very first patients treated with the first Italian installation of a trans-cranial MRI-guided Focused Ultrasound Surgery (tcMRgFUS) certified system for functional neurosurgery. TcMRgFUS is a promising new technique for non-invasive treatment of neurologic disorders such as Essential Tremor, tremor associated to Parkinson's Disease and Neuropathic Pain. TcMRgFUS is able to focally target and destroy specific regions in the brain through intact skull, by using a high intensity focused ultrasound beam. Resting state functional Magnetic Resonance Imaging (RS-fMRI) analyses focuses on spontaneous low frequency …

tcMRgFUS thalatomy functional connectivity fMRI
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Understanding the White-Emitting CaMoO4 Co-Doped Eu3+, Tb3+, and Tm3+ Phosphor through Experiment and Computation

2019

In this article, the synthesis by means of the spray pyrolysis method, of the CaMoO4 and rare-earth cation (RE3+)-doped CaMoO4:xRE3+ (RE3+ = Eu3+, Tb3+, and Tm3+; and x = 1, 2, and 4% mol) compounds, is presented. The as-synthesized samples were characterized using X-ray diffraction, Rietveld refinement, field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and photoluminescence (PL) spectroscopy. To complement and rationalize the experimental results, first-principles calculations, at the density functional theory level, have been performed to analyze the band structure and density of states. In addition, a theoretical method based on the calculations of surface energie…

terbium compoundsMaterials scienceTm3+lightingAnalytical chemistryfield emission microscopes02 engineering and technology010402 general chemistry01 natural sciencesSpray pyrolysiseuropium compoundsTb3+White-Emitting CaMoO4Physical and Theoretical Chemistrydensity functional theorycalcium compoundscomputation theoryenamelsPhosphor021001 nanoscience & nanotechnologyred phosphorselectronic structureCo-Doped Eu3+0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsESTRUTURA ELETRÔNICAGeneral Energyphotoluminescence spectroscopylight emissionphosphors0210 nano-technologyspray pyrolysisCo dopedscanning electron microscopy
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Il primo concorso per il Palazzo di Giustizia a Roma del 1884. Ricostruzione critica del progetto di Ernesto Basile

2019

1. Breve descrizione dell’oggetto di studio Il concorso del Palazzo di Giustizia di Roma si svolge in quattro fasi svolte tra il 1884 e il 1887. Il progetto per il primo concorso, del 1884, redatto dall’allora giovanissimo Ernesto Basile (Palermo 1857-1932), rivela una grande perizia progettuale che trasforma il complesso programma funzionale in un austero edificio in stile neofiorentino. I disegni originari dell’opera, non realizzata, conservati presso la Dotazione Basile del Dipartimento di Architettura dell’Università di Palermo, sono stati oggetto di studio propedeutico alle fasi di analisi, interpretazione e ricostruzione congetturale del modello digitale. 2. Stato dell’arte e riferime…

the spatiality of the great vestibule• elaboration of axonometric and perspective view• choice of interpretation criteria in case of project incongruitiethe vaulted arcades.the space of the main courtyard which Basile outlines in a sketch• elaboration of analytical drawings (modular functional compositional volumetric schemes)• modular study and flat vectorization• application of rendering techniques consistent with the available information. 4. Objectives pursued and achieved Conjectural reconstruction achieved the following results: • formulation of analytical documents which show how the planimetric and altimetric articulation are perfectly consistent with the functional program• definition of the level of uncertainty1. Brief description of the object of study The competition of the Palace of Justice in Rome takes place in four phases between 1884 and 1887. The project for the first competition in 1884 drawn up by the then very young Ernesto Basile (Palermo 1857-1932) reveals a great deal of design expertise that transforms the complex functional program into an austere building in neo-florentine style. The original drawings of the building not realized kept in the Basile Endowment of the Department of Architecture of the University of Palermo have been the subject of preliminary study to the phases of analysis interpretation and conceptual reconstruction of the digital model. 2. State of the art and main bibliographical references The conjectural reconstruction on the basis of drawings and archival documents is a well-established and codified practice thanks to various disciplinary contributions at national and international level. See: F. I. Apollonio Classification Schemes for Visualization of Uncertainty in Digital Hypothetical Reconstruction in M. Sander P. Mieke P. Kuroczyński M. Ioannides 3D Research Challenges in Cultural Heritage II Cham (CH) 2016. G. Antista M. Cannella Ricostruire. Architettura - Storia – Rappresentazione Palermo 2015. For studies related to the examinated project see: E. Mauro E. Sessa I disegni della Collezione Basile Roma 2015. E. Sessa Ernesto Basile. Dall'eclettismo Classicista al Modernismo Palermo 2002. 3. Definition of the methodologies adopted in the research Methodological phases: • historical analysi• survey of the original drawings and dimensional verification of the flat scanSettore ICAR/17 - Disegno• construction of perspective views deduced from the original drawings that highlight: the volumetric hierarchy and the function of the bugnate in the scanning of the masonry ma• three-dimensional modeling
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An experimental and theoretical study of a heptacoordinated tungsten(VI) complex of a noninnocent phenylenediamine bis(phenolate) ligand

2018

Abstract [W(N2O2)(HN2O2)] (H4N2O2 = N,N′-bis(3,5-di-tert-butyl-2-hydroxyphenyl)-1,2-phenylenediamine) with a noninnocent ligand was formed by reaction of the alkoxide precursor [W(eg)3] (eg = the 1,2-ethanediolate dianion) with two equivalents of ligand. The phenol groups on one of the ligands are completely deprotonated and the ligand coordinates in a tetradentate fashion, whereas the other ligand is tridentate with one phenol having an intact OH group. The molecular structure, magnetic measurements, EPR spectroscopy, and density functional theory calculations indicate that the complex is a stable radical with the odd electron situated on the tridentate amidophenoxide ligand. The formal ox…

tungstenDFT calculations010402 general chemistry01 natural scienceslaw.inventionInorganic Chemistrychemistry.chemical_compoundDeprotonationlawOxidation stateMaterials ChemistryMoleculePhysical and Theoretical ChemistryElectron paramagnetic resonanceta116amidophenoxide radical010405 organic chemistryLigandkompleksiyhdisteetvolframielectronic structure0104 chemical sciencesCrystallographyoxidation statesUnpaired electronchemistryAlkoxidenoninnocent ligandDensity functional theoryInorganic Chemistry Communications
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Strictly correlated electrons approach to excitation energies of dissociating molecules

2019

In this work we consider a numerically solvable model of a two-electron diatomic molecule to study a recently proposed approximation based on the density functional theory of so-called strictly correlated electrons (SCE). We map out the full two-particle wave function for a wide range of bond distances and interaction strengths and obtain analytic results for the two-particle states and eigenenergies in various limits of strong and weak interactions, and in the limit of large bond distance. We then study the so-called Hartree-exchange-correlation (Hxc) kernel of time-dependent density functional theory which is a key ingredient in calculating excitation energies. We study an approximation b…

two-electron diatomic moleculeFOS: Physical sciencesElectron01 natural sciences010305 fluids & plasmasCondensed Matter - Strongly Correlated ElectronsQuantum mechanics0103 physical sciencesstrictly correlated electrons010306 general physicsWave functionAdiabatic processta116approximationdensity functional theoryPhysicsStrongly Correlated Electrons (cond-mat.str-el)ta114tiheysfunktionaaliteoriamolekyylitDiatomic moleculeBond lengthDensity functional theoryLocal-density approximationapproksimointiExcitation
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