ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The potential energy surface of the ground state He+Cl2(1Σg) is calculated by using the perturbation theory of intermolecular forces and supermolecular Møller–Plesset perturbation theory approach. The potential energy surface of the first excited triplet He+Cl2(3Πu) was evaluated using the supermolecular unrestricted Møller–Plesset perturbation theory approach. In the ground state two stable isomers are found which correspond to the linear He–Cl–Cl structure (a primary minimum, De=45.1 cm−1, Re=4.25 A(ring)) and to the T-shaped structure with He perpendicular to the molecular axis (a secondary minimum, De=40.8 cm−1, Re=3.5 A(ring)). The small difference between these geometries is mainly due to the induction effect which is larger for the linear form. The results obtained for the T-shaped minimum are in good agreement with the excitation spectroscopy experiments which observed only the T-shaped form [Beneventi et al., J. Chem. Phys. 98, 178 (1993)]. In the lowest triplet states correlating with Cl2(3Πu), 3A' and 3A‘, the same two isomers correspond to minima. Now, however, the T-shaped form is lower in energy. The 3A' and 3A‘ states correspond to (De,Re) of (19.9 cm−1, 3.75 A(ring)) and (30.3 cm−1, 3.50 A(ring)), respectively, whereas the linear form is characterized by (19.8 cm−1, 5.0 A(ring)). The binding energy for the T form in the lower 3A‘ state is in good agreement with the experimental value of Beneventi et al.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.468308
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