An energy-decomposition technique for the analysis of band structure and its application to polyphosphazene and its halogenated derivatives

An energy-decomposition technique is presented for the analysis of band structures of polymers and is applied to the π orbitals of polyphosphazene and its halogenated derivatives. In this treatment the orbital energy is decomposed into the contributions from individual atoms and bonds in the structure. Thereby, the shape of the energy band is elucidated as a function of atomic orbital interactions as well as structures of polymers. The trends of the k dependences for the individual contributions thus analyzed are consistent with those to be expected from the characters of the crystal orbitais. This method seems to be suitable for determining the effects of various substituents on the shape of the energy bands of polymers.