Pade approximants and the calculation of spectral functions of solids
Fernando F. Grinstein · Journal of Physics C Solid State Physics · 1982
The computation approach of Chisholm, Genz and Pusterla (1976) for evaluating Feynman matrix elements in the physical region is proposed for the calculation of spectral functions of solids. The method is based on the moment expansion for the functions, with a convenient choice of reference point, and it resummation with Pade approximants. The technique is tested in the calculation of the electron density of states for a one-dimensional system. In this case, the convergence of the method may be formally proved, while a numerical study shows its practical significance.