title: Communication: A simple full range analytical potential for H2b(3)∑u (+), H-He (2)∑(+), and He2 (1)∑g (.).
abstract: The Tang-Toennies potential for the weakly interacting systems H2b(3)Σu (+), H-He (2)Σ(+), and He2 (1)Σg (+) is extended down to the united atom limit of vanishing internuclear distance. A simple analytic expression connects the united atom limiting potential with the Tang-Toennies potential in the well region. The new potential model is compared with the most recent ab initio calculations for all three systems. The agreement is better than 20% (H2 and He2) or comparable with the differences in the available ab initio calculations (H-He) over six orders of magnitude corresponding to the entire range of internuclear distances.
authors: Max Planck Institute for Dynamic and Self-Organization, Am Fassberg 17, 37077 Goettingen, Germany.
authors: Sascha
authors: S
authors: Warnecke
authors: Department of Physics, Pacific Lutheran University, Tacoma, Washington 98447, USA.
authors: K T
authors: KT
authors: Tang
authors: Max Planck Institute for Dynamic and Self-Organization, Am Fassberg 17, 37077 Goettingen, Germany.
authors: J Peter
authors: JP
authors: Toennies