Structure and properties of Al$^+$

The properties of a number of states of single charged Al$^{+}$ ion are determined from a large basis configuration interaction calculation. The main focus is on the polarizabilities of the low-lying states (the $3s^2$ $^1$S$^e$, $3s3d$ $^{1,3}$D$^e$, $3s3p$ $^{1,3}$P$^o$ and $3s4s$ $^{1,3}$S$^e$ states) and the dispersion interactions of those states with the Al$^{+}$ ground state, the hydrogen atom and the rare gases.