Properties of the Helium Atom

The available theoretical values of the oscillator strengths of dipole transitions from the ground state of helium are modified so that they satisfy four different sum rules. They are then employed to evaluate the refractive index, the Verdet constant, the diamagnetic susceptibility, the Lamb shift, the average energy loss for fast particle impact and the van der Waals interaction between two helium atoms, good agreement being obtained with experimental data where comparison is possible.