标题： 一种对各种形态和尺寸的硅量子点（直至无限大）的电子、光学和结合性质的全面从头算研究 显示英文标题

标题： A Comprehensive Ab Initio Study of Electronic, Optical and Cohesive Properties of Silicon Quantum Dots of Various Morphologies and Sizes up to Infinity

摘要： 我们提出了一种全面且综合的模型无关的第一性原理研究，研究了各种形态和尺寸的硅量子点的结构、结合能、电子和光学性质，在全电子静态和时间依赖密度泛函理论（DFT，TDFT）框架下，使用经过验证的B3LYP和其他适当选择的功能函数。 我们对各种生长模型和尺寸从1到32埃的氢钝化纳米晶体的所有这些性质的原始第一性原理结果，随后通过功率律依赖关系进行拟合，基于维度和其他合理的论据选择适当的指数。 因此，我们不仅能以极高的精度再现重叠区域内的已知实验和经过验证的理论结果，还能成功地外推到无穷大，几乎以化学精度再现晶体硅的带隙，以及以非常高的精度再现无限晶体的结合能。 因此，我们的结果可以安全地用作插值和外推公式，不仅适用于结合能和带隙，还适用于相关性质，如各种尺寸的硅纳米晶体的介电常数和折射率，一直到无穷大。 显示英文摘要

摘要： We present a comprehensive and integrated model-independent ab initio study of the structural, cohesive, electronic, and optical properties of silicon quantum dots of various morphologies and sizes in the framework of all-electron static and time-dependent density functional theory (DFT, TDFT), using the well-tested B3LYP and other properly chosen functional(s). Our raw ab initio results for all these properties for hydrogen passivated nanocrystals of various growth models and sizes from 1 to 32 Angstroms, are subsequently fitted, using power-law dependence with judicially selected exponents, based on dimensional and other plausibility arguments. As a result, we can reproduce with excellent accuracy not only known experimental and well-tested theoretical results in the regions of overlap, but we can also extrapolate successfully all the way to infinity, reproducing the band gap of crystalline silicon with almost chemical accuracy as well as the cohesive energy of the infinite crystal with very good accuracy. Thus, our results could be safely used, among others, as interpolation and extrapolation formulas not only for cohesive energy and band gap, but also for interrelated properties, such as dielectric constant and index of refraction of silicon nanocrystals of various sizes all the way up to infinity.