Contributions of the two conformers to the microwave spectrum and scattering cross-section of the He–Cl2 van der Waals system, evaluated from an ab initio potential energy surface
| Autor: | F. Y. Naumkin, F. R. W. McCourt |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Condensed Matter::Quantum Gases
Chemistry Binding energy Ab initio General Physics and Astronomy Rotational–vibrational spectroscopy Helium compounds symbols.namesake Ab initio quantum chemistry methods Potential energy surface Physics::Atomic and Molecular Clusters symbols Physical and Theoretical Chemistry van der Waals force Atomic physics Ground state |
| Zdroj: | The Journal of Chemical Physics. 108:9301-9312 |
| ISSN: | 1089-7690 0021-9606 |
| DOI: | 10.1063/1.476419 |
| Popis: | A high-level ab initio PES has been calculated for the ground state He–Cl2 complex. The existence and relative depths of the two wells, one for each of the linear (L-well) and T-shaped (T-well) geometries, are shown to be correctly predicted with a simple atom-atom model using ab initio HeCl potentials of equivalent accuracy. Distortions of the He–Cl interaction due to perturbations of the electronic structure of the Cl atoms by strong intramolecular forces in Cl2 are suggested to be responsible for the remaining underestimation of the binding energy. Even though it has a deeper well, the linear configuration is less stable than the T-shaped configuration when zero-point vibrations are taken into account. Although the lowest rovibrational levels of each conformer lie above the potential barrier separating the two wells, the associated wavefunctions reflect the presence of the other well only weakly, as indicated by the low local maxima in the probability densities at the other well positions. The presence... |
| Databáze: | OpenAIRE |
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