论文标题
具有非自动稳定的Kohn-Sham轨道的混合功能的准确性,用于预测半导体的性质
Accuracy of hybrid functionals with non-self-consistent Kohn-Sham orbitals for predicting the properties of semiconductors
论文作者
论文摘要
准确地对材料的电子结构进行建模是对高通量筛选的持续挑战。平衡准确性与计算成本的有前途的方法是与混合密度功能理论的非自愿计算,其中使用来自轨道的混合功能评估了电子带能量,该轨道获得了较少(半)局部功能的轨道。我们已经量化了该技术的性能,以预测16个四面体半导体的物理特性,带有从0.2-5.5 eV的带隙。前提是基本功能预测非金属电子结构,可以在计算时间降低数量级的情况下获得pBE0的5%以内的带隙。价和传统带极值和费米水平的位置得到了很好的再现,从而进一步可以使用费米的黄金规则来计算带分散,状态的密度和介电性能。虽然非元素一致的总能量的误差为〜50 meV atom-1,但能量量曲线的准确地重现了足够的曲线,以获得平衡体积和大量模量,而误差则最小。我们还测试了介电依赖性的SCPBE0功能,并将带隙和介电常数在自洽结果的2.5%以内,这相当于与自搭配PBE0的显着改善,对于类似的计算成本。我们确定了预期非自愿方法的性能较差的案例,并证明部分自我矛盾提供了实用有效的解决方法。最后,我们对COO和NIO进行概念验证计算,以证明该技术对强相关的开壳过渡金属氧化物的适用性。
Accurately modeling the electronic structure of materials is a persistent challenge to high-throughput screening. A promising means of balancing accuracy against computational cost are non-self-consistent calculations with hybrid density-functional theory, where the electronic band energies are evaluated using a hybrid functional from orbitals obtained with a less demanding (semi-)local functional. We have quantified the performance of this technique for predicting the physical properties of sixteen tetrahedral semiconductors with bandgaps from 0.2-5.5 eV. Provided the base functional predicts a non-metallic electronic structure, bandgaps within 5 % of the PBE0 and HSE06 gaps can be obtained with an order of magnitude reduction in computing time. The positions of the valence and conduction band extrema and the Fermi level are well reproduced, further enabling calculation of the band dispersion, density of states, and dielectric properties using Fermi's Golden Rule. While the error in the non-self-consistent total energies is ~50 meV atom-1, the energy-volume curves are reproduced accurately enough to obtain the equilibrium volume and bulk modulus with minimal error. We also test the dielectric-dependent scPBE0 functional and obtain bandgaps and dielectric constants to within 2.5 % of the self-consistent results, which amount to a significant improvement over self-consistent PBE0 for a similar computational cost. We identify cases where the non-self-consistent approach is expected to perform poorly, and demonstrate that partial self-consistency provides a practical and efficient workaround. Finally, we perform proof-of-concept calculations on CoO and NiO to demonstrate the applicability of the technique to strongly-correlated open-shell transition-metal oxides.