Friedrich HundDied 31 Mar 1997 at age 101 (born 4 Feb 1896). Friedrich (Hermann) Hund was a German physicist known for his work on the electronic structure of atoms and molecules. He introduced a method of using molecular orbitals to determine the electronic structure of molecules and chemical bond formation. His empirical Hund's Rules (1925) for atomic spectra determine the lowest energy level for two electrons having the same n and l quantum numbers in a many-electron atom. (1) The lowest energy state has the maximum multiplicity consistent with the Pauli exclusion principle. (2) The lowest energy state has the maximum total electron orbital angular momentum quantum number, consistent with rule (1). They are explained by the quantum theory of atoms by calculations involving the repulsion between two electrons. |
