Departament de Ciència de Materials i Química Física and Institut de Química Teòrica i Computacional (IQTCUB) , Universitat de Barcelona , c/Martí i Franquès 1-11 , 08028 Barcelona , Spain.
J Chem Theory Comput. 2019 Sep 10;15(9):5024-5030. doi: 10.1021/acs.jctc.9b00516. Epub 2019 Aug 15.
The electronic properties of realistic (TiO) nanoparticles (NPs) with cuboctahedral and bipyramidal morphologies are investigated within the many-body perturbation theory (MBPT) approximation using PBE and hybrid PBEx (12.5% Fock contribution) functionals as starting points. The use of a Gaussian and plane waves (GPW) scheme reduces the usual computational time required in this type of calculation close to and thus allows considering explicitly NPs with up to 165. The analysis of the Kohn-Sham energy orbitals and quasiparticle (QP) energies shows that the optical energy gap (), the electronic energy gap (), and the exciton binding energy (Δ) values decrease with increasing TiO NP size, in agreement with previous work. However, while bipyramidal NPs appear to reach the scalable regime already for = 84, cuboctahedral NPs reach this regime only above = 151. Relevant correlations are found and reported that will allow one to predict these electronic properties at the level in even much larger NPs where these calculations are unaffordable. The present work provides a feasible and practical way to approach the electronic properties of rather large TiO NPs and thus constitutes a further step in the study of realistic nanoparticles of semiconducting oxides.
采用基于密度泛函理论的多体微扰理论（MBPT）近似方法，利用 PBE 和混合 PBEx（12.5% Fock 贡献）泛函作为起点，研究了具有立方八面体和双金字塔形态的实际（TiO）纳米粒子（NPs）的电子特性。使用高斯和平面波（GPW）方案可以将这种类型计算中通常所需的计算时间减少到接近，从而可以明确考虑具有多达 165 个原子的 NPs。对 Kohn-Sham 能量轨道和准粒子（QP）能量的分析表明，光学能隙（）、电子能隙（）和激子结合能（Δ）值随着 TiO NP 尺寸的增加而减小，这与之前的工作一致。然而，虽然双金字塔形 NPs 似乎已经在 = 84 时达到了可扩展的范围，但立方八面体 NPs 仅在 = 151 以上时才达到这一范围。还发现了相关的相关性，并进行了报道，这将允许在更大的 NPs 中以 水平预测这些电子特性，而在这些计算不可行的情况下。本工作为研究半导体氧化物的实际纳米粒子提供了一种可行且实用的方法来研究相当大的 TiO NPs 的电子特性，因此是在研究半导体氧化物的实际纳米粒子方面迈出的又一步。
