海归学者发起的公益学术平台
分享信息，整合资源

交流学术，偶尔风月
近来，包括高熵合金（HEAs）和复合合金（CCAs）的多组分合金领域成为新材料计算设计的研究热点。采用无参数化的从头算方法，尤其是使用密度泛函理论的计算，其自由能的计算精度需要达到1 meV/ atom，这为新型多元合金的计算设计带来了严峻的挑战。
由德国斯图加特大学的Blazej Grabowski教授领导的团队，证明了TU-TILD + MTP组合是一种理想的协同互作组合，可有效、准确地计算无序多组分合金的完全振动自由能。他们在TU-TILD中将MTP作为参考电位，用于化学复杂的无序VNbMoTaW高熵合金中，结果表明MTP明显优于其它参考电位。TU-TILD + MTP组合的优异性能的物理机制可能是，振动自由能由相当明确、足够平滑、局部（虽然严格非谐）相空间的一部分来确定。研究表明，该组合方法不仅适用于本研究所涉及的等原子组成，也适用于任意非原子组成，还适用于不同的晶体晶格类型（如hcp或fcc），甚至适用于液相。
该文近期发表于npj Computational Materials 5: 80 (2019)，英文标题与摘要如下，点击左下角“阅读原文”可以自由获取论文PDF。
Ab initio vibrational free energies including anharmonicity for multicomponent alloys 
Blazej Grabowski, Yuji Ikeda, Prashanth Srinivasan, Fritz Körmann, Christoph Freysoldt, Andrew Ian Duff, Alexander Shapeev & Jörg Neugebauer 
The unique and unanticipated properties of multiple principal component alloys have reinvigorated the field of alloy design and drawn strong interest across scientific disciplines. The vast compositional parameter space makes these alloys a unique area of exploration by means of computational design. However, as of now a method to compute efficiently, yet with high accuracy the thermodynamic properties of such alloys has been missing. One of the underlying reasons is the lack of accurate and efficient approaches to compute vibrational free energies—including anharmonicity—for these chemically complex multicomponent alloys. In this work, a density-functional-theory based approach to overcome this issue is developed based on a combination of thermodynamic integration and a machine-learning potential. We demonstrate the performance of the approach by computing the anharmonic free energy of the prototypical five-component VNbMoTaW refractory high entropy alloy. 
扩展阅读
npj: 晶格弛豫调控高熵合金—机器学习势
npj：高强度难熔复合固溶体合金——通过电子结构筛选
npj: 畸变对称性—高效寻找最低能量路径
npj: 生物医用功能化纳米粒子——理论、模拟和设计
npj: 状态方程哪个好，密度泛函去寻找
本文系网易新闻·网易号“各有态度”特色内容
媒体转载联系授权请看下方
继续阅读
阅读原文