A numerical study of the asymptotic convergence characteristics of partial averaged and reweighted Fourier path integral methods



The asymptotic convergence characteristics with respect to the number of included path variables of the partial average and reweighted Fourier path integral methods are numerically compared using a Gaussian fit to the one-dimensional Lennard-Jones potential. Using harmonic inversion to determine the parameters of the Gaussian fit potential appropriate for neon, the energy eigenvalues and thermodynamic properties of the Gaussian fit and the Lennard-Jones interaction agree to better than 1%. Using Monte Carlo methods to study the Gaussian fit potential, the systematic error associated with the truncation of the number of path variables is found to be larger for the reweighted method than the partial average method for the same number of path variables actually used. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009