Search results for " lithium compounds"

showing 4 items of 4 documents

Computation of conical intersections by using perturbation techniques

2005

Multiconfigurational second-order perturbation theory, both in its single-state multiconfigurational second-order perturbation theory (CASPT2) and multistate (MS-CASPT2) formulations, is used to search for minima on the crossing seams between different potential energy hypersurfaces of electronic states in several molecular systems. The performance of the procedures is tested and discussed, focusing on the problem of the nonorthogonality of the single-state perturbative solutions. In different cases the obtained structures and energy differences are compared with available complete active space self-consistent field and multireference configuration interaction solutions. Calculations on dif…

Potential Energy SurfacesConfiguration Interactions ; Perturbation Theory ; Potential Energy Surfaces ; Molecular Electronic States ; SCF Calculations ; Lithium Compounds ; Organic Compounds ; Wave FunctionsOrganic CompoundsChemistryComputationUNESCO::FÍSICAConfiguration InteractionsGeneral Physics and AstronomyMultireference configuration interactionConical surfaceSCF CalculationsPotential energyWave FunctionsMaxima and minima:FÍSICA [UNESCO]Molecular Electronic StatesQuantum mechanicsPerturbation TheoryLithium CompoundsStatistical physicsComplete active spacePerturbation theory (quantum mechanics)Physical and Theoretical ChemistryWave functionThe Journal of Chemical Physics
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Multi-line NIR-RGB emission in Nd:LiNbO3 RPE optical waveguides

2007

Simultaneous generation of four spectral emission lines has been achieved in Nd-doped lithium niobate reverse proton exchange optical waveguide cavities. Using a pump at 800 nm, the four lines were found and they are due to lasing at 1.3735 combined with parametric conversion at 0.687, 0.574 and 0.4 mum.

PhotoluminescenceMaterials scienceProtonbusiness.industryLithium niobatechemistry.chemical_elementNeodymiumion exchange lithium compounds neodymium optical pumping optical waveguides photoluminescenceSettore ING-INF/01 - ElettronicaOptical pumpingchemistry.chemical_compoundOpticschemistryRGB color modelElectrical and Electronic EngineeringbusinessLasing thresholdLine (formation)
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Assessment for the mean value total dressing method: Comparison with coupled cluster including triples methods for BF, NO+, CN+, C2, BeO, NH3, CH2, H…

1997

Limited previous experience with the mean value total dressing (MVTD) method had shown that MVTD energies for closed shell systems are generally better than CCSD(T) ones compared to FCI. The method, previously published as total dressing 2′(td-2′), is based on the single reference intermediate Hamiltonian theory. It is not a CC method but deals in a great part with the same physical effects that CC methods that incorporate amplitudes of triples such as CCSDT or its CCSDT-1n approaches. A number of test calculations comparing to diverse CC methods, as well as FCI and experiment when available, have been performed. The tests concern equilibrium energies in NH3 and CH2, equilibrium energies an…

Carbon compoundsGeneral Physics and AstronomyBoron compounds ; Nitrogen compounds ; Water ; Ammonia ; Ozone ; Organic compounds ; Carbon compounds ; Beryllium compounds ; Hydrogen compounds ; Silicon compounds ; Lithium ; Lithium compounds ; Carbon ; Neon compounds ; Coupled cluster calculations ; Dissociation ; Dissociation energies ; Positive ionsLithiumDissociation (chemistry)Nitrogen compoundsIonDissociation energiesOzoneCoupled cluster calculationsAmmoniaBeryllium compoundsOrganic compoundsMoleculeSilicon compoundsPhysical and Theoretical Chemistry:FÍSICA::Química física [UNESCO]Open shellChemistryNeon compoundsMean valueWaterLithium compoundsHydrogen compoundsDiatomic moleculeCarbonUNESCO::FÍSICA::Química físicaCoupled clusterAmplitudeBoron compoundsPositive ionsAtomic physicsDissociation
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Near-field scanning optical microscopy to study nanometric structural details of LiNbO3 Zn-diffused channel waveguides

2008

A near-field scanning optical microscope (NSOM) is used to perform structural and optical characterization of the surface layer after Zn diffusion in a channel waveguide fabricated on lithium niobate. A theoretical approach has been developed in order to extract refractive index contrast from NSOM optical transmission measurements (illumination configuration). As a result, different solid phases present on the sample surface can be identified, such as ZnO and ZnNb2O6. They appear like submicrometric crystallites aligned along the domain wall direction, whose origin can be ascribed to some strain relaxation mechanism during the annealing process after Zn diffusion. Jose.Canet-Ferrer@uv.es

Materials scienceLithium niobateRefractive indexGeneral Physics and AstronomyWaveguide (optics)law.inventionAnnealingchemistry.chemical_compoundAnnealing ; Crystallites ; Lithium compounds ; Nanostructured materials ; Near-field scanning optical microscopy ; Optical waveguides ; Refractive index ; StoichiometryOpticsOptical microscopelaw:FÍSICA [UNESCO]Refractive index contrastSurface layerNear-field scanning optical microscopyÓpticabusiness.industryUNESCO::FÍSICACrystallitesFísicaLithium compoundsNanostructured materialsStoichiometryOptical waveguideschemistryNear-field scanning optical microscopeCrystallitebusinessRefractive index
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