Accelerating Evaluation of Converged Lattice Thermal Conductivity
邀请人： 张晓亮 副教授，能动学院极端条件热物理与能源系统课题组
报告时间：2017-11-14 星期二 10:00-11:30
Designing materials with specific properties is a long-term goal in materials science. High-throughput ab-initio materials screening and design is a new and rapidly growing area in computational materials research. The application of high-throughput calculations has recently made formidable progress and led to novel insights in this field. The lattice thermal conductivity (κ) is a crucial physical property of crystalline materials for enormous practical implications, such as electronic cooling, thermoelectrics, phase change memories, etc. Therefore, the fast evaluation of reliable κ for variety of materials plays a key role in identifying suitable materials for targeted applications. Currently, first-principles based anharmonic lattice dynamics (ALD) method coupled with phonon Boltzmann transport equation (BTE) is one of the most featured methods to obtain the κ, which involves calculation of interatomic force constants (IFCs). Especially, the anharmonic IFCs are evaluated based on the third order derivatives of the total energy with respect to the atomic displacements, which requires huge computational costs. However, severe problem arises for choosing an appropriate (usually not large enough) cutoff distance (rcutoff) when calculating the anharmonic IFCs. Thus, the high-throughput evaluation of reliable κ remains a challenge due to the large resources costs and time-consuming procedures in calculating the anharmonic IFCs for the convergence test.
In this talk, based on the analysis of the harmonic (second order) IFCs, I would like to introduce a concise strategy to efficiently accelerate the evaluation process of obtaining accurate and converged κ by solving the cutoff distance problem. The quantitative strategy proposed herein can be a good candidate for fast evaluating the reliable κ and thus provides useful tool for high-throughput materials screening and design with targeted thermal transport properties.
秦光照，现为德国亚琛工业大学（RWTH Aachen University, Germany）在读博士，从事纳米材料力学性质、电子结构、晶格振动、声子热输运等的第一性原理计算研究，主要关注微纳尺度能量输运问题和热力学性质。截止于17年10月份，总计发表2个Book chapters，2个软件著作权，以及28篇SCI论文，主要发表在Nano Lett., Phys. Rev. B, Nanoscale, Carbon, Appl. Phys. Lett.等知名国际学术期刊，并多次在各种国际学术会议做口头报告。Google Scholar总引用505，h因子为9。