The Virial Theorem in Quantum Chemistry: Its Impact on undergraduate instruction 

For the past 100 years one focus of quantum chemistry has been the occupied canonical orbitals and the associated canonical orbital energies of a given atomic or molecular system. We will show that, at least for atoms, there is another very important set of orbital energies: "virial" orbital energies. They are easily obtained from commonly available electronic structure applications. We will define the virial orbital energies, and show some important applications. We will also show that they correlate several aspects of the electronic structure of atoms, and clear up considerable confusion that exists in textbooks and in the research literature. Buckle your seatbelt!