Dataset for: Identifying Aspirin Polymorphs from Combined DFT-Based Crystal Structure Prediction and Solid-State NMR

A combined experimental and computational approach was used to distinguish between different polymorphs of the pharmaceutical drug aspirin. This method involves the use of Ab Initio Random Structure Searching (AIRSS), a DFT-based crystal structure prediction method for the high-accuracy prediction of polymorphic structures, with DFT calculations of NMR parameters and solid-state NMR experiments at natural abundance. AIRSS was used to predict the crystal structures of form-I and form-II of aspirin. The root-mean-square deviation (RMSD) between experimental and calculated 1H chemical shifts was used to identify form-I as the polymorph present in the experimental sample, the selection being successful despite the large similarities between the molecular environments in the crystals of the two polymorphs.

本研究采用实验与计算相结合的策略，对药用阿司匹林的不同晶型进行区分。该方法运用了从头算随机结构搜索（Ab Initio Random Structure Searching, AIRSS）——一种基于密度泛函理论（Density Functional Theory, DFT）的晶体结构预测方法，可高精度预测晶型结构；同时结合了核磁共振（Nuclear Magnetic Resonance, NMR）参数的DFT计算，以及天然丰度条件下的固态核磁共振实验。研究利用AIRSS预测了阿司匹林I型与II型晶型的晶体结构，并通过对比实验与计算得到的1H化学位移的均方根偏差（Root-Mean-Square Deviation, RMSD），将实验样品中存在的晶型鉴定为I型；尽管两种晶型的晶体分子环境极为相似，该鉴定仍取得了成功。