Interpretation of temperature-dependent terahertz spectra by the first-principles calculations, and hydrogen-bonded networks

本工作旨在系统揭示在温度相关的太赫兹（THz）频谱中检测到的氢键网络中的键合/断裂，以及太赫兹波的应用及其益处。通过大规模、高精度的计算，我们分析了苯甲酸、水杨酸和乙酰水杨酸类似物的温度依赖太赫兹光谱，它们具有不同的氢键网络和典型的晶体结构。特别是对弱氢键进行了色散校正计算，在完全几何优化后，原子坐标和晶格参数的误差在1~ 2%以内，成功地再现了实验结构。本研究表明，对具有弱相互作用的分子晶体的复杂太赫兹光谱进行色散校正的第一性原理计算，大大提高了谱峰分配。

This work aims at the systematic reveal of bonding/breaking in hydrogen-bonded networks those are detected in the temperature-dependent terahertz (THz) spectrum, and at the application of THz wave with their benefit. With large-scale and high-accurate calculations, we have analyzed the temperature-dependent THz spectra of the analogue of benzoic acid, salicylic acid and acetyl salicylic acid, those have different hydrogen-bonded networks and typical crystal structures each other. Especially, we performed the calculations with dispersion corrections those well describe the weak hydrogen bond, and succeeded in reproducing the experimental structures in the atomic coordinates and lattice parameters within the error of 1~2 % after the full geometry optimization. With the present study, it is indicated that the peak assignments are much improved with the dispersion-corrected first-principles calculations for complicated THz spectra of molecular crystals with weak interactions.