Molecular treatment of charge transfer inLi++Ca collisions

The perturbed-stationary-state method, appended with electron translation factors, has been applied to charge transfer in ${\mathrm{Li}}^{+}$ +Ca collisions for energies from 0.1 to 20 keV/amu. The Born-Oppenheimer wave functions and eigenvalues were generated using the pseudopotential technique, which reduced the many-electron system to a simpler two-electron problem. The molecular ground-state $X{}_{}{}^1{}_{}{}^{}\Sigma _{}^{+}{}_{}{}^{}$ is calculated to be bound and has the potential-well parameters $R_e=6.20\mathrm{}{a}_0$, $D_e=1.11\mathrm{}$ eV, ${\omega }_e=235\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$, and $B_e=0.263\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$. From the scattering computations, a representative value for the charge-transfer cross section is 4×${10}^{-15\mathrm{}}$ ${\mathrm{cm}}^2$ at 5 keV/amu. The cross section decreases rapidly as the energy is reduced below 1 keV/amu. At all energies studied, the dominant electron-capture reaction product is the ground-state Li atom.