Jamieson, Mikaela AbegailDalgarno, AlexanderAymar, MTharamel, J2020-05-262009Jamieson, M. J., A. Dalgarno, M. Aymar, and J. Tharamel. 2009. A Study of Exchange Interactions in Alkali Molecular Ion Dimers with Application to Charge Transfer in Cold Cs. Journal of Physics B: Atomic, Molecular and Optical Physics 42, no. 9 (April 21): 095203.0953-4075http://nrs.harvard.edu/urn-3:HUL.InstRepos:42668761The formulation of Bardsley et al (Phys. Rev. A 11 1911) for evaluating the asymptotic electron exchange interaction between an alkali ion and its parent atom is extended by the use of a more accurate representation of the asymptotic wavefunction of the isolated atom and also by the inclusion of a further term in the series that accounts for the presence of the ion. The Bardsley analysis is compared with a purely numerical approach in which the Holstein–Herring integrand is constructed from a polarized wavefunction built from numerical solutions of the differential equations of Rayleigh–Schrodinger perturbation theory and the ¨ required quadrature is performed numerically. Values of the asymptotic exchange interactions are given for the molecular ions Li+ 2 , Na+ 2 , K+ 2 , Rb+ 2 and Cs+ 2 . As an example, exchange interactions for Cs+ 2 evaluated by an ab initio method are compared to those predicted by the Bardsley formula. Potentials for the lowest states of Cs+ 2 are constructed from the ab initio values matched to the asymptotic exchange and long-range polarization interactions, and these potentials are used to predict the 12+ g and 12+ u scattering lengths and low-energy charge transfer cross sections.en-USJournal Article2020-05-2610.1088/0953-4075/42/9/095203