I have seen the fourier transform of the coulomb potential quite often.(adsbygoogle = window.adsbygoogle || []).push({});

However, I have come across a sum expression for an electrostatic potential

[tex]V_{cb}(r-r') = \frac{1}{V}\sum_{q \neq 0} \frac{4\pi}{q^2}e^{iq(r-r')}[/tex]

It is equation (2.6) here: http://people.web.psi.ch/mudry/FALL01/lecture03.pdf

I have assumed this is the coulomb integral. Is it? Has anyone come across such an expression before? Is it valid to take such an expansion for the coulomb integral in a box of finite volume, under the Jellium model?

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# Unusual coulomb potential

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