He is a hydrogenic ion with nuclear charge and a single electron
PHYSICS · Subjective · Fermi University Physics · Atomic, Molecular & Optical Physics · One-electron atoms and the origins of atomic structure · Radiative transitions, external fields and collisions
Deriving the Spectrum, Ch Atoms in electric fields
Problem
He+ is a hydrogenic ion with nuclear charge Z=2 and a single electron. Hydrogen's ground-state polarisability closure bounds are 316a03(upper, closure),2.96a03(lower, 2p term alone). For a hydrogenic ion of charge Z, lengths scale as a0/Z and energy gaps scale as Z2Eh, both relative to hydrogen (Z=1). Use this scaling to find the corresponding upper and lower bounds on the ground-state polarisability of He+, in units of a03 (the ordinary, unscaled Bohr radius).