Optimization algorithm for the generation of ONCV pseudopotentials

TLDR

The authors develop an optimization algorithm to generate Optimized Norm‑Conserving Vanderbilt pseudopotentials for elements up to bismuth, excluding lanthanides. They define a quality function comparing pseudopotential calculations to all‑electron FLAPW results, then apply Nelder–Mead optimization on a training set of materials and validate the resulting potentials on an independent test set. The automatically constructed pseudopotentials show good agreement with all‑electron FLEUR calculations at a plane‑wave cutoff of approximately 60 Ry.

Abstract

We present an optimization algorithm to construct pseudopotentials and use it to generate a set of Optimized Norm-Conserving Vanderbilt (ONCV) pseudopotentials for elements up to Z=83 (Bi) (excluding Lanthanides). We introduce a quality function that assesses the agreement of a pseudopotential calculation with all-electron FLAPW results, and the necessary plane-wave energy cutoff. This quality function allows us to use a Nelder–Mead optimization algorithm on a training set of materials to optimize the input parameters of the pseudopotential construction for most of the periodic table. We control the accuracy of the resulting pseudopotentials on a test set of materials independent of the training set. We find that the automatically constructed pseudopotentials (http://www.quantum-simulation.org) provide a good agreement with the all-electron results obtained using the FLEUR code with a plane-wave energy cutoff of approximately 60 Ry.