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Open Access item Transition state dynamics of OHF on several electronic states: Photodetachment spectrum of OHF- and conical intersections
Gómez Carrasco, Susana
Hernández, M. Luz
Alvariño, José M.
|Keywords:||Electron detachment, Transition moments, Triplet state, Ground states, Potential energy surfaces, Ab initio calculations, Molecule-photon collisions, Reaction kinetics, Vibronic states, Negative ions, Molecular configurations, Oxygen compounds, Hydrogen compounds, Wave functions, Molecular electronic states, [PACS] Autoionization, photoionization, and photodetachment of molecules, [PACS] Molecular oscillator and band strengths, lifetimes, transition moments, and Franck–Condon factors, [PACS] Potential energy surfaces for excited electronic states (atoms and molecules), [PACS] Potential energy surfaces for ground electronic states (atoms and molecules), [PACS] Ab initio calculations (atoms and molecules), [PACS] Transition state theory and statistical theories of rate constants (chemical kinetics), [PACS] Vibronic, rovibronic, and rotation-electron-spin interactions (molecular spectra), [PACS] General molecular conformation and symmetry; stereochemistry|
|Publisher:||American Institute of Physics|
|Citation:||Journal of Chemical Physics 121(20): 9865 (2004)|
|Abstract:||Wave packet simulations of the photodetachment spectrum of OHF– are performed on several electronic adiabatic states, two triplets and four singlets of neutral OHF. The transition moments to these six states have been approximated using the ab initio electronic wave functions of OHF– and OHF calculated at the equilibrium configuration of the parent anion. In a first step, two-dimensional simulations of the spectrum are performed on new two-dimensional potential energy surfaces (PESs) of the neutral in a OHF collinear geometry. The resulting simulated spectrum is in rather good agreement with the experimental one, reproducing all the structures from 0 to 2.5 eV electron kinetic energies. At energies below 0.5 eV, all calculated states, singlets and triplets, contribute to the total spectrum. At higher energies, however, only the triplet states participate. In a second step, to improve the description of the spectrum, three-dimensional wave packet simulations of the spectrum are performed, getting an excellent agreement with the experiment. The collinear 3Σ– and 3Π states split in two 3A'' and one 3A'. New adiabatic PESs are used in this work for the 2 3A'' and 1 3A' states, while the one recently proposed was used for the ground 1 3A''. It is found that the minimum energy paths of the 3Σ– and 3Π states cross twice at collinear geometry, so that at the transition state the ground state corresponds to 3Π, while 3Σ– is the lowest state otherwise. Such conical intersections are expected to give rise to important Σ-Π vibronic effects, requiring a complete three-dimensional model of coupled diabatic states to improve our understanding of the reaction dynamics in this kind of systems.|
|Description:||11 pages, 12 figures, 1 table.-- PACS nrs.: 33.80.Eh; 33.70.Ca; 31.50.Df; 31.50.Bc; 31.15.Ar; 82.20.Db; 33.20.Wr; 33.15.Bh.|
|Publisher version (URL):||http://dx.doi.org/10.1063/1.1807375|
|Appears in Collections:||(CFMAC-IFF) Artículos|
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