Filtering a distribution simultaneously in real and Fourier space
Eduardo Anglada, José M. Soler · Physical Review B · 2006
We present a method to filter a distribution so that it is confined within a sphere of given radius ${r}_{c}$ and, simultaneously, whose Fourier transform is optimally confined within a sphere of radius ${k}_{c}$. Our procedure may have several applications in the field of electronic structure methods, like the generation of optimized pseudopotentials and localized pseudocore charge distributions. As an example, we describe a particular application within the SIESTA method for density functional calculations, in removing the spurious rippling of the energy surface generated by the integrations in a real-space grid.