论文标题
有效学习一维密度功能理论
Efficient Learning of a One-dimensional Density Functional Theory
论文作者
论文摘要
密度功能理论是用于电子结构预测固体的最成功和最广泛使用的数值方法。但是,它具有根本的缺点,即通用密度函数尚不清楚。此外,计算结果 - 基态的能量和电荷密度分布 - 对于基于Kohn-Sham方法的频带结构解释,主要是固体的电子性质。在这里,我们演示了机器学习算法如何有助于从这些局限性中释放密度功能理论。我们研究了一维晶格上无旋转费的理论。密度功能由神经网络隐式表示,该神经网络可预测地面能量和密度分布,密度密度相关函数。我们绝对不需要频带结构解释。通过精确的对角化获得的培训数据源于受主动学习启发的学习方案,从而最大程度地减少了数据生成的计算成本。我们表明,网络结果具有很高的定量精度,尽管学习了随机电位,但正确地捕获了对称性的断裂和拓扑相变。
Density functional theory underlies the most successful and widely used numerical methods for electronic structure prediction of solids. However, it has the fundamental shortcoming that the universal density functional is unknown. In addition, the computational result---energy and charge density distribution of the ground state---is useful for electronic properties of solids mostly when reduced to a band structure interpretation based on the Kohn-Sham approach. Here, we demonstrate how machine learning algorithms can help to free density functional theory from these limitations. We study a theory of spinless fermions on a one-dimensional lattice. The density functional is implicitly represented by a neural network, which predicts, besides the ground-state energy and density distribution, density-density correlation functions. At no point do we require a band structure interpretation. The training data, obtained via exact diagonalization, feeds into a learning scheme inspired by active learning, which minimizes the computational costs for data generation. We show that the network results are of high quantitative accuracy and, despite learning on random potentials, capture both symmetry-breaking and topological phase transitions correctly.