Generalizations of Perelomov's identity on the completeness of coherent   states
  We proof the Perelomov identity for arbitrary 2D lattices using Fourier transformation. We further generalize it to situations where the origin does not coincide with a lattice site, and where the form of the exponential factor is reminiscent of magnetic wave functions in uniaxial rather than symmetric gauge. 
Martin Greiter, Ronny Thomale
cond-mat.str-el