Elliptical electron orbits

The Bohr-Sommerfeld atom model suggests that electron orbits can be elliptical, not just circular. This refinement explained more details in spectral lines and integrated relativity and quantum theory.
 Arnold Johannes Wilhelm Sommerfeld Germany 1915 Elliptical electron orbits

The Bohr-Sommerfeld atom model suggests that electron orbits can be elliptical, not just circular. This refinement explained more details in spectral lines and integrated relativity and quantum theory.