Application of molecular orbital graph theory to vibrational problems of finite chain systems

A generating function approach based on molecular orbital graph theory is presented that provides a straightforward way of obtaining the secular polynomials and energy bands for repeated unit systems from polynomial recurrence expressions. The possibility of obtaining the analytical energy‐level spectrum of the system can also be predicted. These results are then used to discuss the vibrational problems of finite chain systems with single‐ and double‐component lattices. It seems to be the first report describing the vibrational states of an (AB)N chain.