Electron-impact excitation of Zn II. II

Collision strengths are calculated for excitation of Zn II from the $4s$ ground state to excited states $4p,3d^{9}4s^2,5s, \mathrm{and} 4d$ in a five-state close-coupling approximation for the electron-impact energy range $15<E<\mathrm{}400\mathrm{}$ eV, and from $4s \mathrm{to} 4p,5s, \mathrm{and} 3p^{5}3d^{10}4s^2$ in a two-state close-coupling approximation for the same energy range. Accurate target functions are used in the expansion. Very good agreement with measurements of absolute emission cross sections of Rogers et al. is obtained for energy region $15<E<\mathrm{}100\mathrm{}$ eV, when cascade contributions are included. Poorer agreement is obtained with experiment for excitation of the $5s$ state, owing to sensitivities in the close-coupling approximation.