Polarizability of atomic hydrogen consider a semi classical model of the ground state of the hydrogen atom in an electric field normal to the plane of the orbit (Fig. 25), and show that for this model a = a³_H;, where a_H, is the radius of the unperturbed orbit. Note: If the applied field is in the x direction, then the x component of the field of the nucleus at the displaced position of the electron orbit must be equal to the applied field. The correct quantum-mechanical result is larger than this by the factor 9/2. (We are speaking of a₀ in the expansion a = a₀, + a₁ E + . . . .) We assume x H. One can also calculate al on this model.

Proton Electron CE