Search results for "Transition moments"

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Electronic excited states of conjugated cyclic ketones and thioketones : A theoretical study

2002

Absorption spectra of a series of cyclic conjugated ketones and thioketones have been computed at the multiconfigurational second-order multistate perturbation level of theory, the CASSCF/MS-CASPT2 method. Excitation energies, transition dipole moments, oscillator strengths, and static dipole moments are reported and discussed for excited states with energies lower than ≈ 7–8 eV. The main bands of the spectra have been assigned and characterized in most cases for the first time. The spectroscopy of the different systems is compared in detail. Thioketones in particular have low-energy and intense ππ∗ transitions which suggest corresponding enhanced nonlinear molecular optical properties. Add…

Molecular MomentsAbsorption spectroscopyChemistryOrganic CompoundsTransition MomentsGeneral Physics and AstronomyOscillator StrengthsExcited StatesConjugated systemSCF CalculationsSpectral lineUNESCO::FÍSICA::Química físicaDipoleExcited stateTheoretical chemistryPhysical and Theoretical ChemistryAtomic physicsOrganic Compounds ; Excited States ; SCF Calculations ; Molecular Moments ; Oscillator Strengths ; Transition MomentsSpectroscopy:FÍSICA::Química física [UNESCO]Excitation
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Full configuration interaction calculation of singlet excited states of Be3

2004

The full configuration interaction (FCI) study of the singlets vertical spectrum of the neutral beryllium trimer has been performed using atomic natural orbitals [3s2p1d] basis set. The FCI triangular equilibrium structure of the ground state has been used to calculate the FCI vertical excitation energies up to 4.8 eV. The FCI vertical ionization potential for the same geometry and basis set amounts to 7.6292 eV. The FCI dipole and quadrupole transition moments from the ground state are reported as well. The FCI electric quadrupole moment of the X (3)A(1) (') ground state has been also calculated with the same basis set (Theta(zz)=-2.6461 a.u., Theta(xx)=Theta(yy)=-1/2Theta(zz)). Twelve of …

Atomic clustersElectron correlationsIonisation potentialGeneral Physics and AstronomyFull configuration interactionBeryllium ; Configuration interactions ; Excited states ; Orbital calculations ; Ground states ; Ionisation potential ; Molecular configurations ; Transition moments ; Quadrupole moments ; Molecular moments ; Electron correlations ; Atomic clustersPhysical and Theoretical Chemistry:FÍSICA::Química física [UNESCO]Basis setElectronic correlationChemistryConfiguration interactionsExcited statesPhysics::Physics EducationMolecular configurationsTransition momentsUNESCO::FÍSICA::Química físicaOrbital calculationsGround statesDipoleExcited stateQuadrupoleQuadrupole momentsMolecular momentsBerylliumAtomic physicsIonization energyGround stateThe Journal of Chemical Physics
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