0000000000263222

AUTHOR

Flemming Hegelund

showing 3 related works from this author

Abstracts of the 6th FECS Conference 1998 Lectures.

1998

International audience

[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere010504 meteorology & atmospheric sciencesHealth Toxicology and MutagenesisMEDLINE[CHIM.CATA]Chemical Sciences/CatalysisGeneral Medicine010501 environmental sciences01 natural sciencesPollutionEngineering physics[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]Environmental ChemistryEnvironmental scienceEngineering ethics[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]ComputingMilieux_MISCELLANEOUS0105 earth and related environmental sciencesEnvironmental science and pollution research international
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Molecular equilibrium structures from experimental rotational constants and calculated vibration–rotation interaction constants

2002

A detailed study is carried out of the accuracy of molecular equilibrium geometries obtained from least-squares fits involving experimental rotational constants B(0) and sums of ab initio vibration-rotation interaction constants alpha(r)(B). The vibration-rotation interaction constants have been calculated for 18 single-configuration dominated molecules containing hydrogen and first-row atoms at various standard levels of ab initio theory. Comparisons with the experimental data and tests for the internal consistency of the calculations show that the equilibrium structures generated using Hartree-Fock vibration-rotation interaction constants have an accuracy similar to that obtained by a dir…

FREQUENCIESChemistryGAUSSIAN-BASIS SETSAb initioGeneral Physics and AstronomyDiatomic moleculeSTATEBORONBond lengthVibrationHOFMETHANEMolecular geometryCCSD(T) 2ND DERIVATIVESAb initio quantum chemistry methodsACIDWAVE-FUNCTIONSPhysics::Atomic and Molecular ClustersMoleculeQUARTIC FORCE-FIELDPhysics::Chemical PhysicsPhysical and Theoretical ChemistryAtomic physicsRotation (mathematics)The Journal of Chemical Physics
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The equilibrium structure of trans-glyoxal from experimental rotational constants and calculated vibration–rotation interaction constants

2003

A total of six high-resolution FT-IR spectra for trans-glyoxal-d2, trans-glyoxal-d1 and trans-glyoxal-13C2 were recorded with a resolution ranging from 0.003 to 0.004 cm−1. By means of a simultaneous ground state combination difference analysis for each of these isotopologues using the Watson Hamiltonian in A-reduction and Ir-representation the ground state rotational constants are obtained. An empirical equilibrium structure is determined for trans-glyoxal using these experimental ground state rotational constants and vibration–rotation interaction constants calculated at the CCSD(T)/cc-pVTZ level of theory. The least-squares fit yields the following structural parameters for trans-glyoxal…

ChemistryGeneral Physics and AstronomyInfrared spectroscopyThermodynamicsSpectral linesymbols.namesakeComputational chemistryKinetic isotope effectsymbolsMoleculeIsotopologueRotational spectroscopyPhysical and Theoretical ChemistryHamiltonian (quantum mechanics)Ground statePhys. Chem. Chem. Phys.
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