An empirical potential-energy surface for the He-I2(B 3Πu) van der Waals complex including three-body effects -: art. no. 124311

An empirical intermolecular potential surface is proposed for the He-I-2(B (3)Pi(u)) complex, modeled as a sum of pairwise He-I Morse interactions plus a three-body interaction term. The potential reproduces with very good agreement the spectral blueshifts and vibrational predissociation lifetimes measured for He-I-2(B,upsilon') in the range upsilon'=10-67 of I-2 vibrational excitations. In particular, the accuracy achieved in the description of the experimental data for high upsilon(') levels is attributed to the three-body interaction term included in the potential. The behavior of the potential surface with the I-I separation is analyzed and correlated with the experimental findings. (c) 2005 American Institute of Physics.