Collision Spectroscopy of the SystemLi2+

Differential scattering measurements are reported for the elastic reaction ${\mathrm{Li}}^{+}$ + Li →${\mathrm{Li}}^{+}$ + Li at 25-150 eV (c.m.) and the inelastic reaction ${\mathrm{Li}}^{+}+\mathrm{Li}\left(2s{}_{}{}^2{}_{}{}^{}S\right)\to {\mathrm{Li}}^{+}+\mathrm{Li}\left(2p{}_{}{}^2{}_{}{}^{}P\right)$ at 25, 50, and 100 eV. The elastic cross sections show a rainbow peak at $E{\theta }_R\cong 80$ eV deg, curve-crossing perturbations, and possibly electron-transfer oscillations. The inelastic cross sections have an oscillatory structure with a threshold at $E{\theta }_X\cong 70$ eV deg. These observations are interpreted in terms of the diabatic electronic states of ${\mathrm{Li}}_2^{+}$.