Accelerating The Convergence Of Force Calculations In Electronic-Structure Computations

The Hellmann-Feynman forces in local-density-functional calculations are very sensitive to the self-consistency of the charge or the screening potential. This is due to the omission of a correction term that is frequently ignored. This term can be calculated approximately using a very simple ansatz, which is very easy to code and consumes negligible amounts of computer time, and yet can lead to substantial improvement in the convergence of forces with respect to self-consistency.