Epstein Zeta Function

where and are arbitrary Vectors, the Sum runs over a -dimensional Lattice, and is omitted if is a lattice Vector.

Glasser, M. L. and Zucker, I. J. Lattice Sums in Theoretical Chemistry.'' Theoretical Chemistry: Advances and Perspectives, Vol. 5. New York: Academic Press, pp. 69-70, 1980.
Shanks, D. Calculation and Applications of Epstein Zeta Functions.'' Math. Comput. 29, 271-287, 1975.