Wavefunction tight-binding model

Fig. 4.6. Band dispersion in the tight binding model (a) for a symmetric (even) atomic wavefunction and (b) for an antisymmetric (odd) atomic wavefunction.

A rather different model for the trapped electron in alkane glasses has been proposed recently by Funabashi and Moruyama [151]. The excess electron is described in the tight-binding approximation in which its wavefunction is expressed as a linear combination of the wavefunctions for the individual negative ions. Optical transition probabilities between the lowest ground state and all the other states were computed. The calculated absorption spectrum is in qualitative agreement with the experimental one. More results and theoretical developments are needed in the field before a definite conclusion can be reached. 

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