Madrid Institute for Advanced Studies, IMDEA Nanoscience Madrid, Spain.
Front Chem. 2013 Dec 13;1:35. doi: 10.3389/fchem.2013.00035. eCollection 2013.
We present a conceptual approach to low bandgap copolymers, in which we clarify the physical parameters which control the optical bandgap, develop a fundamental understanding of bandgap tuning, unify the terminology, and outline the minimum requirements for accurate prediction of polymer bandgaps from those of finite length oligomers via extrapolation. We then test the predictive power of several popular hybrid and long-range corrected (LC) DFT functionals when applied to this task by careful comparison to experimental studies of homo- and co-oligomer series. These tests identify offset-corrected M06HF, with 100% HF exchange, as a useful alternative to the poor performance of tested hybrid and LC functionals with lower fractions of HF exchange (B3LYP, CAM-B3LYP, optimally-tuned LC-BLYP, BHLYP), which all significantly overestimate changes in bandgap as a function of system size.
我们提出了一种低带隙共聚物的概念方法，其中我们澄清了控制光学带隙的物理参数，对带隙调谐有了基本的了解，统一了术语，并概述了通过外推从有限长度低聚物预测聚合物带隙的准确性的最低要求。然后，我们通过仔细比较同系列和共聚低聚物的实验研究，测试了几种流行的混合和长程校正（LC）DFT 泛函在该任务中的预测能力。这些测试确定了经偏移校正的 M06HF（100% HF 交换），作为混合和 LC 泛函（B3LYP、CAM-B3LYP、最佳调谐 LC-BLYP、BHLYP）的较差性能的有用替代，这些泛函的 HF 交换分数较低（B3LYP、CAM-B3LYP、最佳调谐 LC-BLYP、BHLYP），所有这些都显著高估了带隙随系统尺寸的变化。
