Eur. Phys. J. D 24, 169-172 (2003)
https://doi.org/10.1140/epjd/e2003-00142-5

A theoretical study on electron transfer in low-energy collisions of a collinear meta-stable Na₃⁺ with a Na

¹ Laboratoire de Physique des Solides, Université Paris-Sud, 91405 Orsay Cedex, France
² College of Science and Technology Nihon University, Funabashi 274-8501, Japan

Corresponding author: ^a mooming@phys.ge.cst.nihon-u.ac.jp

Received: 10 September 2002
Published online: 3 July 2003

Abstract

Electron transfer in the collisions of a Na with a Na is theoretically studied. It is assumed that the target Na is collinear () and that its electronic state is meta-stable triplet () state. Adiabatic potential energy surfaces and non-adiabatic couplings of the Na system are calculated by using a semi-empirical diatomics-in-molecules (DIM) method. The positions of (avoided)-crossings of potential surfaces are investigated and the non-adiabatic couplings between two different electronic states are calculated. An avoided crossing is found in the region where the separation between the target and projectile is relatively large (10–15 bohr). A dynamical calculation demonstrates that this crossing causes charge transfer between the target and projectile. Another intersection at a smaller separation changes the target's spin state (from triplet state to singlet state or vice versa). The cross-sections for charge and spin transfer reaction are estimated at the collision energy of 6.8 keV. It is found that the charge transfer cross-section is extremely enhanced when the target cluster ion is in its meta-stable triplet state comared to the case where the cluster is the ground singlet state.