We present a joint theoretical and experimental study to investigate polymorphism in $α$-sexithiophene (6T) crystals. By means of density-functional theory calculations, we clarify that the low-temperature phase is favorable over the high-temperature one, with higher relative stability by about 50 meV/molecule. This result is in agreement with our thermal desorption measurements. We also propose a transition path between the high- and low-temperature 6T polymorphs, estimating an upper bound for the energy barrier of about 1 eV/molecule. The analysis of the electronic properties of the investigated 6T crystal structures complements our study.
van der Waals forces stabilize low-energy polymorphism in B2O3: Implications for the crystallization anomaly
最近预测的，从来没有合成，B $_2$ O $_3$多晶型的结合能和结构特性进行了研究，从第一性原理使用密度泛函理论和高精度多体方法，即随机相近似和量子蒙特卡罗。我们表明，范德华力在使实验已知的多晶型物（B $_2$ O $_3$ -I）的能量最低，许多竞争亚稳结构只躺在几千卡/摩尔以上的关键作用。值得注意的是，所有亚稳晶体在能量和密度上都与玻璃相当，同时具有各向异性和机械柔软的结构。此外，根据我们的稳定性标准，最佳亚稳多晶型物具有在玻璃和最近合成的硼硫酸盐化合物中发现的结构基序。我们的发现为理解B $_2$ O $_3$的反常行为提供了新的视角，即它在玻璃态结构中的玻璃化倾向与已知晶体截然不同。
Engineering Excitons through Polymorphism and Dimensional Confinement in Low-Dimensional Tellurium
Federal University of Goi\'as, Institute of Physics, Campus Samambaia, 74960600 Goi\ ania, Brazil；Institute of Physics, Computational Materials Laboratory, University of Bras \' i lia, Bras \' i lia, 70910-900, Brazil
Electron-phonon couplings in polymorphous crystals
Univ Rennes, INSA Rennes, CNRS, Institut FOTON（雷恩大学、雷恩国立应用科学学院、法国国家科学研究中心、FOTON研究所）；Computation-based Science and Technology Research Center, The Cyprus Institute（塞浦路斯研究院计算科学与技术研究中心）；Univ Rennes, ENSCR, INSA Rennes, CNRS, ISCR（雷恩大学、雷恩高等师范学院、雷恩国立应用科学学院、法国国家科学研究中心、ISCR）；Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin（德克萨斯大学奥斯汀分校奥登计算工程与科学学院）；Department of Physics, The University of Texas at Austin（德克萨斯大学奥斯汀分校物理系）
Synthetic control over marcasite-pyrite polymorph formation in the Fe1-xCoxSe2 series
Ruhr University Bochum（鲁尔大学波鸿分校）；University of Duisburg-Essen（杜伊斯堡-埃森大学）；Institute for Energy and Materials Processes (EMPI)（能源与材料过程研究所）；Interdisciplinary Centre For Advanced Materials Simulation (ICAMS)（先进材料模拟跨学科中心）；Research Center Future Energy Materials and Systems (RC FEMS)（未来能源材料与系统研究中心）；Institute for Materials（材料研究所）；Center for Interface-Dominated High Performance Materials (ZGH)（界面主导高性能材料中心）
Shizuoka University（静冈大学）；The University of Tokyo（东京大学）；Okayama University（冈山大学）；Hiroshima University（广岛大学）；Japan Synchrotron Radiation Research Institute（日本同步辐射研究所）；Tokyo University of Science（东京理科大学）；Nagoya University（名古屋大学）
