Accurate kinetic energy evaluation in electronic structure calculations with localized functions on real space grids
We present a method for calculating the kinetic energy of localized functions represented on a regular real space grid. This method uses fast Fourier transforms applied to restricted regions commensurate with the simulation cell and is applicable to grids of any symmetry. In the limit of large systems it scales linearly with system size. Comparison with the finite difference approach shows that our method offers significant improvements in accuracy without loss of efficiency. (C) 2001 Elsevier Science B.V. All rights reserved.
kinetic energy finite difference density functional theory linear-scaling fft