Polarizabilities of the Ps negative ion

Abstract

We have calculated polarizabilities (${\ensuremath{\alpha}}_{1}$, ${\ensuremath{\beta}}_{1}$, ${\ensuremath{\gamma}}_{1}$, ${\ensuremath{\alpha}}_{2}$, ${\ensuremath{\beta}}_{2}$, and ${\ensuremath{\gamma}}_{2}$) of ${\mathrm{Ps}}^{\ensuremath{-}}$ by the pseudostate method. These parameters can be used to calculate Rydberg states of ${\mathrm{Ps}}^{\ensuremath{-}}$ in the presence of an external electron with high quantum numbers $N$ and $L$. They are also of importance in a system containing ${\mathrm{Ps}}^{\ensuremath{-}}$ bound to a proton [PsH] and also Rydberg states of ${\mathrm{Ps}}_{2}$.