Search results for "Electron Spectra"

showing 10 items of 20 documents

Ab initio determination of the ionization potentials of DNA and RNA nucleobases

2006

Quantum chemical high level ab initio coupled-cluster and multiconfigurational perturbation methods have been used to compute vertical and adiabatic ionization potentials of the five canonical DNA and RNA nucleobases: uracil, thymine, cytosine, adenine, and guanine. Several states of their cations have been also calculated. The present results represent a systematic compendium of these magnitudes, establishing theoretical reference values at a level not reported before, calibrating computational strategies, and guiding the assignment of the features in the experimental photoelectron spectra. Daniel.Roca@uv.es Mercedes.Rubio@uv.es Manuela.Merchan@uv.es Luis.Serrano@uv.es

DNA ; Macromolecules ; Ionisation potential ; Photoelectron spectra ; Molecular biophysics ; Ab initio calculations ; Coupled cluster calculations ; Perturbation theoryGuanineGuaninePhotochemistryAb initioBiophysicsGeneral Physics and AstronomyIonisation potentialPerturbation theoryNucleobasechemistry.chemical_compoundCytosinePhotoelectron spectraCoupled cluster calculationsAb initio quantum chemistry methodsComputational chemistryIonizationPhysics::Atomic and Molecular ClustersPhysical and Theoretical ChemistryUracil:FÍSICA::Química física [UNESCO]IonsPhysics::Biological PhysicsQuantitative Biology::BiomoleculesBase CompositionChemistry PhysicalAdenineUracilDNAMolecular biophysicsQuantitative Biology::GenomicsThymineUNESCO::FÍSICA::Química físicachemistryMacromoleculesCalibrationQuantum TheoryRNAAb initio calculationsCytosineSoftwareThymine
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Towards an accurate molecular orbital theory for excited states : Ethene, butadiene, and hexatriene

1993

A newly proposed quantum chemical approach for ab initio calculations of electronic spectra of molecular systems is applied to the molecules ethene, trans‐1,3‐butadiene, and trans‐trans‐1,3,5‐hexatriene. The method has the aim of being accurate to better than 0.5 eV for excitation energies and is expected to provide structural and physical data for the excited states with good reliability. The approach is based on the complete active space (CAS) SCF method, which gives a proper description of the major features in the electronic structure of the excited state, independent of its complexity, accounts for all near degeneracy effects, and includes full orbital relaxation. Remaining dynamic ele…

ErrorsGeneral Physics and AstronomyPolyenesElectronic structuresymbols.namesakeRydberg StatesAb initio quantum chemistry methodsComputational chemistrySinglet statePhysical and Theoretical ChemistryTriplet state:FÍSICA::Química física [UNESCO]AccuracyExcitationCalculation MethodsButadieneTripletsChemistryMolecular orbital theoryScf CalculationsExcited StatesCalculation Methods ; Quantum Chemistry ; Ab Initio Calculations ; Electron Spectra ; Butadiene ; Accuracy ; Scf Calculations ; Triplets ; Rydberg States ; Excitation ; Errors ; Polyenes ; Excited StatesQuantum ChemistryUNESCO::FÍSICA::Química físicaElectron SpectraExcited stateRydberg formulasymbolsRydberg stateAtomic physicsAb Initio Calculations
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Thin film growth and band lineup of In2O3 on the layered semiconductor InSe

1999

Thin films of the transparent conducting oxide In2O3 have been prepared in ultrahigh vacuum by reactive evaporation of indium. X-ray diffraction, optical, and electrical measurements were used to characterize properties of films deposited on transparent insulating mica substrates under variation of the oxygen pressure. Photoelectron spectroscopy was used to investigate in situ the interface formation between In2O3 and the layered semiconductor InSe. For thick In2O3 films a work function of φ = 4.3 eV and a surface Fermi level position of EF−EV = 3.0 eV is determined, giving an ionization potential IP = 7.3 eV and an electron affinity χ = 3.7 eV. The interface exhibits a type I band alignmen…

Materials scienceAnalytical chemistryIonisation potentialGeneral Physics and AstronomyWork functionPhotoelectron spectrasymbols.namesakeX-ray photoelectron spectroscopyIndium compounds:FÍSICA [UNESCO]Electron affinityWork functionThin filmbusiness.industryFermi levelUNESCO::FÍSICAHeterojunctionInterface statesBand structureEvaporation (deposition)X-ray diffractionElectron affinitySemiconductorVacuum depositionIndium compounds ; Vacuum deposition ; X-ray diffraction ; Photoelectron spectra ; Semiconductor-insulator boundaries ; Work function ; Fermi level ; Ionisation potential ; Electron affinity ; Interface states ; Band structureFermi levelsymbolsSemiconductor-insulator boundariesOptoelectronicsbusiness
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"Table 6" of "Dielectron and heavy-quark production in inelastic and high-multiplicity proton-proton collisions at $\sqrt{s_{\rm NN}}$ = 13 TeV"

2018

Ratio of dielectron spectra in HM and INEL events scaled by the charged-particle multiplicity as a function of invariant mass for $p_{\rm T,ee}$ < 1.0 GeV/$c$.

NEE_HM/NEE_INELP P --> E+ E- X13000.0High Energy Physics::ExperimentRatio of dielectron spectraNuclear Experiment
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"Table 5" of "Dielectron and heavy-quark production in inelastic and high-multiplicity proton-proton collisions at $\sqrt{s_{\rm NN}}$ = 13 TeV"

2018

Ratio of dielectron spectra in HM and INEL events scaled by the charged-particle multiplicity as a function of invariant mass for $p_{\rm T,ee}$ < 6.0 GeV/$c$.

NEE_HM/NEE_INELP P --> E+ E- X13000.0High Energy Physics::ExperimentRatio of dielectron spectraNuclear Experiment
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"Table 8" of "Dielectron and heavy-quark production in inelastic and high-multiplicity proton-proton collisions at $\sqrt{s_{\rm NN}}$ = 13 TeV"

2018

Ratio of dielectron spectra in HM and INEL events scaled by the charged-particle multiplicity as a function of invariant mass for 2.0 < $p_{\rm T,ee}$ < 3.0 GeV/$c$.

NEE_HM/NEE_INELP P --> E+ E- X13000.0Ratio of dielectron spectra
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"Table 7" of "Dielectron and heavy-quark production in inelastic and high-multiplicity proton-proton collisions at $\sqrt{s_{\rm NN}}$ = 13 TeV"

2018

Ratio of dielectron spectra in HM and INEL events scaled by the charged-particle multiplicity as a function of invariant mass for 1.0 < $p_{\rm T,ee}$ < 2.0 GeV/$c$.

NEE_HM/NEE_INELP P --> E+ E- X13000.0Ratio of dielectron spectra
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"Table 9" of "Dielectron and heavy-quark production in inelastic and high-multiplicity proton-proton collisions at $\sqrt{s_{\rm NN}}$ = 13 TeV"

2018

Ratio of dielectron spectra in HM and INEL events scaled by the charged-particle multiplicity as a function of invariant mass for 3.0 < $p_{\rm T,ee}$ < 6.0 GeV/$c$.

NEE_HM/NEE_INELP P --> E+ E- X13000.0Ratio of dielectron spectra
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An experimental comparison of the K- and L-Auger electron spectra generated in the decays of 140Nd and 111In

2005

The low-energy electron spectra generated in the decay of 140Nd have been measured using a combined electrostatic spectrometer adjusted to the 4, 7, and 35 eV instrumental resolution. In order to estimate the therapeutic potential of low-energy electrons associated with the decay of 140Nd, similar experiments have been performed with 111In. Relative Auger electron intensity ratios per decay are: 111In(K-Auger)/140Nd(K-Auger)=1.47(12), 111In(L-Auger) /140Nd(L-Auger)=1.1(4), and 111In(L-Auger [2.8-7 keV])/140Nd(L-Auger [2.8-7 keV])=0.24(11). The obtained K-Auger group intensity ratios have been compared with results of calculations. The good agreement found for the experimental and estimated …

NeodymiumRadioisotopesAuger electron spectroscopyRadiationSpectrometerRelative intensityChemistryElectron spectraSpectrum AnalysisResolution (electron density)Soft Tissue NeoplasmsDNA NeoplasmElectronSpectral lineAtomic physicsAtomic dataApplied Radiation and Isotopes
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New Features in the Systematics of Low‐Spin States in Even 106‐120Cd

1991

Low‐spin states in even 106‐112Cd and 116Cd were investigated by in‐beam and off‐beam γ‐ray and conversion‐electron spectroscopy. New spin assignments and decay branching ratios for the levels in 106Cd,108Cd,110Cd and 112Cd were obtained. From the new systematical data for the even 106‐120Cd, it is inferred that two sets of low‐lying 0+ states cross between 114Cd and 116Cd. One of these sets appears to have features of both intruder and two‐quadrupole‐phonon states.

Nuclear physicsSystematicsPhysicsSpin statesBranching fractionElectron spectraExcited stateIsotopes of cadmiumGamma spectroscopyAtomic physicsSpectroscopyAIP Conference Proceedings
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