论文标题
非常高温的Kohn-Sham密度功能模拟的要求以及如何绕过它们
Requirements for very high temperature Kohn-Sham density functional simulations and how to bypass them
论文作者
论文摘要
在高温密度的功能理论模拟（从数十个EV到KEV）中，Kohn-Sham轨道的总数是获得准确结果的关键数量。为了确定轨道数量与最高轨道的职业水平之间的关系，我们根据有限温度下的电子气质得出了一个模型。该模型可以预测达到给定职业水平的轨道总数，从而获得规定的精度。必须考虑低至10-4及以下的职业水平以比1％更好地收敛结果，这使高温模拟非常耗时，超过几十EV。在评估了模型对先前结果和ABINIT最小化的预测之后，我们展示了Zhang等人的扩展FPMD方法。 [POP 23 042707，2016]允许在高温下对轨道数量绕过这些强大的约束。
In high temperature density functional theory simulations (from tens of eV to keV) the total number of Kohn-Sham orbitals is a critical quantity to get accurate results. To establish the relationship between the number of orbitals and the level of occupation of the highest orbital, we derived a model based on the electron gas properties at finite temperature. This model predicts the total number of orbitals required to reach a given level of occupation and thus a stipulated precision. Levels of occupation as low as 10-4, and below, must be considered to get converged results better than 1%, making high temperature simulations very time consuming beyond a few tens of eV. After assessing the predictions of the model against previous results and ABINIT minimizations, we show how the extended FPMD method of Zhang et al. [PoP 23 042707, 2016] allows to bypass these strong constraints on the number of orbitals at high temperature.
