CAREER: Role of Symmetry in the Properties of Nanostructures: A First Principles Approach

这个教师早期职业发展（CAREER）计划将开发一个廉价的高保真计算框架，用于加速发现具有前所未有的特性的纳米结构，这些特性可以根据技术应用进行定制。纳米结构可以定义为具有至少一个纳米范围内的尺寸的结构。这些系统所表现出的显著特性导致了纳米技术的革命性领域，其潜在应用包括可再生能源的高效生产和储存;绝症的诊断和治疗;有效的净化过程;以及具有高强度重量比的新材料的合成。设计具有非常适合于此类应用的增强性质的纳米结构的能力特别重要。然而，天文学上大量的纳米结构配置和组成使得系统的搜索不切实际。因此，目前的实验和计算技术通常依赖于经验的洞察力，这使得过程冗长，昂贵，容易失败。综合教育目标是将多学科纳米科学/纳米技术相关课程纳入K-12，本科和研究生教育。纳米结构的对称性，无论是完整的还是破碎的，在决定其非凡特性方面起着关键作用。为了理解和利用这种依赖性的目标，一个新的真实空间，自适应配方和大规模并行实施从头算密度泛函理论将开发。该配方与所有对称群的兼容性将导致计算成本的极大降低，从而使纳米结构的准确表征比目前可行的尺寸大三个数量级。此外，开发的配方将使系统发现新的纳米结构与深奥的属性，允许使用对称性的纳米结构的配置空间的有效参数化。待研究的应用包括纳米级挠曲电，这将提供新的理解极化和应变梯度之间的耦合的性质和强度;在噬菌体T4病毒的尾鞘的相变，这将提供重要的见解到病毒的结构和创建;和搜索新的纳米结构，显示独特的现象凭借线性色散关系。总的来说，拟议的研究代表了传统观点的范式转变，即具有平移对称性的晶体单元是基本的构建块。

This Faculty Early Career Development (CAREER) program will develop an inexpensive high-fidelity computational framework for the accelerated discovery of nanostructures with unprecedented properties that can be tailored to technological applications. Nanostructures can be defined as structures which possess at least one dimension in the nanometer range. The remarkable properties displayed by such systems have resulted in the revolutionary field of nanotechnology, whose potential applications include the efficient production and storage of renewable energy; diagnosis and cure of terminal illnesses; effective purification processes; and synthesis of new materials with high strength to weight ratio. The capability to design nanostructures with enhanced properties that are well suited to such applications is of particular importance. However, the astronomically large number of nanostructure configurations and compositions makes a systematic search impractical. Therefore, current experimental and computational techniques typically rely on empirical insight, which makes the process lengthy, expensive and susceptible to failure. The integrated educational objective is to incorporate multi-disciplinary nanoscience/nanotechnology related curriculum into the K-12, undergraduate and graduate education. The symmetry of nanostructures, either intact or broken, plays a key role in determining their extraordinary properties. Towards the goal of understanding and utilizing this dependence, a novel real-space, symmetry-adapted formulation and massively parallel implementation of ab-initio Density Functional Theory will be developed. The compatibility of this formulation with all the symmetry groups will result in a tremendous reduction in the computational cost, thereby enabling the accurate characterization of nanostructures that are three orders of magnitude larger in size than those currently feasible. Additionally, the developed formulation will enable the systematic discovery of new nanostructures with esoteric properties by allowing for an efficient parametrization of the configurational space of nanostructures using symmetry. The applications to be studied include nanoscale flexoelectricity, which will provide new understanding into the nature and strength of the coupling between polarization and strain gradients; phase transformation of the tail sheath in the bacteriophage T4 virus, which will provide significant insights into the structure and creation of viruses; and search for new nanostructures that display unique phenomena by virtue of a linear dispersion relation. Overall, the proposed research represents a paradigm shift from the conventional view that crystal unit cells with translational symmetry are the fundamental building blocks.