Divergence of Dipole Sums and the Nature of Non-Lorentzian Exponentially   Narrow Resonances in One-Dimensional Periodic Arrays of Nanospheres
  Origin and properties of non-Lorentzian spectral lines in linear chains of nanospheres are discussed. The lines are shown to be super-exponentially narrow with the characteristic width proportional to exp[-C(h/a)^3] where C is a numerical constant, h the spacing between the nanospheres in the chain and a the sphere radius. The fine structure of these spectral lines is also investigated. 
Vadim A. Markel