基于从头算多体微扰理论的金刚石纳米颗粒的准粒子电子结构与光吸收
Quasiparticle electronic structure and optical absorption of diamond nanoparticles from ab initio many-body perturbation theory.
作者信息
Yin Huabing, Ma Yuchen, Hao Xiaotao, Mu Jinglin, Liu Chengbu, Yi Zhijun
机构信息
School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
出版信息
J Chem Phys. 2014 Jun 7;140(21):214315. doi: 10.1063/1.4880695.
The excited states of small-diameter diamond nanoparticles in the gas phase are studied using the GW method and Bethe-Salpeter equation (BSE) within the ab initio many-body perturbation theory. The calculated ionization potentials and optical gaps are in agreement with experimental results, with the average error about 0.2 eV. The electron affinity is negative and the lowest unoccupied molecular orbital is rather delocalized. Precise determination of the electron affinity requires one to take the off-diagonal matrix elements of the self-energy operator into account in the GW calculation. BSE calculations predict a large exciton binding energy which is an order of magnitude larger than that in the bulk diamond.
采用GW方法和含时密度泛函理论中的贝叶斯-萨尔皮特方程（BSE），在从头算多体微扰理论框架下研究了气相中小直径金刚石纳米颗粒的激发态。计算得到的电离势和光学带隙与实验结果相符，平均误差约为0.2电子伏特。电子亲和能为负，最低未占据分子轨道相当离域。精确确定电子亲和能需要在GW计算中考虑自能算符的非对角矩阵元。BSE计算预测出一个较大的激子结合能，比体相金刚石中的激子结合能大一个数量级。
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