Lower Excited States of Helium Atom

http://demonstrations.wolfram.com/LowerExcitedStatesOfHeliumAtom/ The Wolfram Demonstrations Project contains thousands of free interactive visualizations, with new entries added daily. The ground state of the helium atom has the electronic configuration 1s^2 1^1 S. In the lowest excited states, an electron is promoted from the 1s to a 2s or 2p orbital. Although the hydrogenic 2s and 2p orbitals are degenerate, the 1s 2s configuration ... Contributed by: S. M. Blinder