The Poisson Comb Function Formula for Series

Quantum Nanochemistty-Volume I Quantum Theory and Observability 

In this series the coefficient of the Fourier expansion has the expression  

Moreover, when the terms of the last relation are multiplied with the inte- 

The final expression seems, at the first sight, like a complicated version of the initial series (the left hand side), whereas in the concrete applications it proves to be a very useful transformation of the initial series into a convergent one. 

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