Eigenvalue distributions in alternant hydrocarbons

摘要

A theorem due to Lord Rayleigh is applied to the graphs and bual graphs of conjugated hydrocarbon molecules to show how the distribution of their eigenvalues can be understood. A lower bound to the number of eigenvalues larger than or equal to 2 can be predicted easily from the graphs. The uses of the theorem as applied to polyenes, non-alternants and polyhex are illustrated.