发表机构
National Taiwan University; National Center for Theoretical Sciences（国立台湾大学; 国家理论科学中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究采用热辅助占据密度泛函理论（TAO-DFT）系统研究梯形苯类化合物（n-LPs）的电子性质，发现其自由基特征随尺寸增加呈现阻尼周期振荡，为纳米材料设计提供指导。
AI 中文摘要
准确预测具有自由基特征的扩展π共轭体系的电子性质仍然是一个重大的理论挑战。为了克服这一挑战，近年来发展了热辅助占据密度泛函理论（TAO-DFT）。在本研究中，我们采用TAO-DFT系统地探索了梯形苯类化合物（n-LPs）的电子性质，这些化合物包含n个稠合的四元碳环。我们的计算表明，所有研究的n-LPs（n = 1 ~ 40）均具有单重态基态。随着n-LP尺寸的增加，我们观察到从较小n-LPs的非自由基特征到较大n-LPs的多自由基特征的转变。值得注意的是，我们在n-LPs的自由基特征中识别出一种明显的阻尼周期振荡，在特定间隔（n = 3k - 1，其中k为正整数）处具有高度相关的热点。活性轨道的实空间表示证实，这种全局电子行为由活性轨道沿中心梯形骨架的结构局域化所支配。这些发现为n-LPs的尺寸依赖性电子性质提供了基本见解，为其在未来纳米材料应用中的合理设计提供了指导。
英文摘要
Accurate prediction of the electronic properties of extended $π$-conjugated systems with radical character remains a major theoretical challenge. To overcome this challenge, thermally-assisted-occupation density functional theory (TAO-DFT) has been developed in recent years. In this study, we employ TAO-DFT to systematically explore the electronic properties of ladder-type phenylenes ($n$-LPs), containing $n$ fused four-membered carbon rings. Our calculations reveal that all investigated $n$-LPs (with $n$ = 1 ~ 40) possess singlet ground states. With increasing $n$-LP size, we observe a transition from the nonradical character of smaller $n$-LPs to the polyradical character of larger $n$-LPs. Notably, we identify a distinct damped periodic oscillation in the radical character of $n$-LPs, featuring highly correlated hotspots at specific intervals ($n = 3k - 1$, where $k$ are positive integers). The real-space representation of active orbitals confirms this global electronic behavior is governed by the structural localization of active orbitals along the central ladder framework. These findings provide fundamental insights into the size-dependent electronic properties of $n$-LPs, guiding their rational design for future nanomaterial applications.
Comments27 pages, 12 figures
