Low-temperature rate coefficients for vibrational relaxation of (3)Σ(u)(+)Rb2 molecules by (3)He and (4)He atoms.
We present quantum-scattering calculations of (4)He and (3)He colliding with (87)Rb2. For both helium isotopes, the elastic and inelastic rate coefficients are strongly influenced by the J = 1 partial wave. For the lighter isotope, a strong resonance feature of the J = 1 partial wave is responsible for an extremely efficient vibrational relaxation process. We also perform bound-state calculations of the Rb2He complex for even Rb permutation symmetry and nonzero total angular momentum. The global Rb2He (3)Σu(+) potential-energy surface used supports four bound states for (4)He and a single one for (3)He. We propose an analysis of the (87)Rb2(4)He spectrum separating the contributions of Rb2 rotation and helium motion.
Institut de Physique de Rennes , UMR 6251 CNRS & Université de Rennes 1, 263 av. du Général Leclerc, F-35042 Rennes, France.
Alexandra
A
Viel
Jean-Michel
JM
Launay