Linear-scaling first-principles molecular dynamics with plane-waves accuracy

We propose a real-space finite differences approach for accurate and unbiased O(N) density functional theory molecular dynamics simulations based on a localized orbitals representation of the electronic structure. The discretization error can be reduced systematically by adapting the mesh spacing, while the orbitals truncation error decreases exponentially with the radius of the localization regions. For regions large enough, energy conservation in microcanonical simulations is demonstrated for liquid water. We propose an explanation for the energy drift observed for smaller regions.