We revisit the problem of calculating amplitude at infinity for class functions with power-law behavior by means a resummation procedure based on truncated series small variables. Iterative Borel summation is applied employing Padé approximants “odd” and “even” types modified to satisfy power-law. The odd approximations are conventional asymptotically equivalent an number terms in series. Even ...

Some methods for the convergence acceleration of the Møller-Plesset perturbation series for the correlation energy are discussed. The order-by-order summation is less effective than the Feenberg series. The latter is obtained by renormalizing the unperturbed Hamilton operator by a constant factor that is optimized for the third order energy. In the fifth order case, the Feenberg series can be i...