We present the one-orbital ensemble self-consistent field (OE-SCF), an alternative orbital-free DFT solver that extends the applicability of DFT to beyond nanoscale system sizes, retaining the accuracy required to be predictive. OE-SCF treats the Pauli potential as an external potential updating it iteratively, dramatically outperforming current solvers because only few iterations are needed to reach convergence. OE-SCF enabled us to carry out the largest ab initio simulations for silicon-based materials to date by employing only 1 CPU. We computed the energy of bulk-cut Si nanoparticles as a function of their diameter up to 16 nm, and the polarization and interface charge transfer when a Si slab is sandwiched between two metal slabs where lattice matching mandated a large contact area. Additionally, OE-SCF opens the door to adopting even more accurate functionals in orbital-free DFT simulations while still tackling large system sizes.

中文翻译：

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高效的DFT求解器，可用于纳米级仿真及其他领域

我们提出了一个单轨道整体自洽场（OE-SCF），这是一种替代性的无轨道DFT求解器，它将DFT的适用性扩展到了超过纳米级的系统尺寸，并保留了可预测的精度。OE-SCF将Pauli势作为迭代更新的外部势，将其性能大大优于当前的求解器，因为只需很少的迭代即可达到收敛。OE-SCF使我们能够进行最大的从头算迄今为止，仅使用1个CPU即可对硅基材料进行仿真。我们计算了整体切割的Si纳米颗粒的能量随其直径（最大可达16 nm）的变化，以及将Si平板夹在两个金属平板之间的情况下的极化和界面电荷转移，其中晶格匹配要求较大的接触面积。此外，OE-SCF为在无轨道DFT模拟中采用甚至更精确的功能打开了大门，同时仍然可以解决大型系统的问题。