Interpolating moving least-squares methods for fitting potential-energy surfaces:Further improvement of efficiency via cutoff strategies

摘要

In standard applications of interpolating moving least squares (IMLS)for fitting a potential-energy surface (PES),all available ab initio points are used.Because remote ab initio points negligibly influence IMLS accuracy and increase IMLS time-to-solution,we present two methods to locally restrict the number of points included in a particular fit.The fixed radius cutoff (FRC)method includes ab initio points within a hypersphere of fixed radius.The density adaptive cutoff (DAC)method includes points within a hypersphere of variable radius depending on the point density.We test these methods by fitting a six-dimensional analytical PES for hydrogen peroxide.Both methods reduce the IMLS time-to-solution by about an order of magnitude relative to that when no cutoff method is used.The DAC method is more robust and efficient than the FRC method.