sasPDF, a method for characterizing the structure of nanoparticle assemblies (NPAs), is presented. The method is an extension of the atomic pair distribution function (PDF) analysis to the small-angle scattering (SAS) regime. The PDFgetS3 software package for computing the PDF from SAS data is also presented. An application of the sasPDF method to characterize structures of representative NPA samples with different levels of structural order is then demonstrated. The sasPDF method quantitatively yields information such as structure, disorder and crystallite sizes of ordered NPA samples. The method was also used to successfully model the data from a disordered NPA sample. The sasPDF method offers the possibility of more quantitative characterizations of NPA structures for a wide class of samples.

中文翻译：

---

SASPDF：根据小角度散射数据对纳米粒子组装体进行对分布函数分析

提出了 sasPDF，一种表征纳米粒子组装体 (NPA) 结构的方法。该方法是原子对分布函数 (PDF) 分析到小角散射 (SAS) 范围的扩展。还介绍了用于从 SAS 数据计算 PDF 的 PDFgetS3 软件包。然后演示了 sasPDF 方法应用来表征具有不同结构顺序级别的代表性 NPA 样品的结构。sasPDF 方法定量产生有序 NPA 样品的结构、无序度和微晶尺寸等信息。该方法还成功地对来自无序 NPA 样本的数据进行了建模。sasPDF 方法提供了对各类样品的 NPA 结构进行更多定量表征的可能性。