Strong Analytic Controllability for Hydrogen Control Systems
  The realization and representation of so(4,2) associated with the hydrogen atom Hamiltonian are derived. By choosing operators from the realization of so(4,2) as interacting Hamiltonians, a hydrogen atom control system is constructed, and it is proved that this control system is strongly analytically controllable based on a time-dependent strong analytic controllability theorem. 
Chunhua Lan, Tzyh-Jong Tarn, Quo-Shin Chi, John W. Clark