arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2005.00277cond-mat.mtrl-sci
收藏

具有非自洽Kohn-Sham轨道的杂化泛函预测半导体性质的精度

Accuracy of hybrid functionals with non-self-consistent Kohn-Sham orbitals for predicting the properties of semiconductors

Jonathan M. Skelton, David S. D. Gunn, Sebastian Metz, Stephen C. Parker

摘要:

精确建模材料的电子结构是高通量筛选的持续挑战。平衡精度与计算成本的一种有前途的方法是用混合密度泛函理论进行非自洽计算,其中使用来自用要求较低的(半)局部泛函获得的轨道的混合泛函来评估电子能带能量。我们已经量化了这种技术的性能预测的物理性质的16四面体半导体的带隙从0.2-5.5 eV。提供的基础功能预测的非金属电子结构,PBE 0和HSE 06间隙的5%以内的带隙可以得到一个数量级的计算时间减少。的价带和导带极值和费米能级的位置被很好地再现,进一步使能带色散,态密度,和介电性能的计算使用费米的黄金法则。虽然在非自洽的总能量的误差是~50毫电子伏原子-1,能量-体积曲线被准确地再现,以获得平衡体积和体积模量的误差最小。我们还测试了介电依赖的scPBE 0功能,并获得带隙和介电常数的自洽结果的2.5%内,这相当于一个显着的改善自洽PBE 0为类似的计算成本。我们确定的情况下,非自我一致的方法预计表现不佳,并证明部分自我一致性提供了一个实用和有效的解决方案。最后,我们对CoO和NiO进行了概念验证计算,以证明该技术对强相关开壳过渡金属氧化物的适用性。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑