Fundamental Nanomechanics with SCC-DFTB Objective Molecular Dynamics

基础纳米力学与 SCC-DFTB 目标分子动力学

• 批准号: 1332228
• 负责人: Traian Dumitrica
• 金额: $ 40万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1332228&HistoricalAwards=false
• 关键词: Fundamental; Nanomechanics; SCC; DFTB; Objective

The research objective of this award is to understand and model the helical structure and mechanics of amyloid fibrils, and the stability and mechanical energy storage in helical zinc oxide nanostructures. Because these structures exist on a scale comparable to interatomic distances, atomistic detail is essential to understanding their behavior. The planned nanomechanical computations are prohibitive with current quantum methods, which are dependent on the translational symmetry of crystalline solids. They become possible, however, with the new objective molecular dynamics method coupled with the self-consistent-charge density-functional tight-binding. This coupling relies on a proposed generalization of the Ewald method to a helical charge distribution. Preliminary results indicate that this generalization is feasible and could enable efficient nanostructure and biomolecule simulations. If successful, the methodology will allow for the first time the evaluation of electrostatic fields generated by discrete charge distributions over helical structures in modern materials and life sciences on a quantitative level. The amyloid fibril studies, aimed at understanding key atomistic details, mechanical properties and correlations between polymorphism and mechanical response, will help elucidate molecular mechanisms in Alzheimer's and other prion diseases. Also, they will have implications for the meso-scale modeling of amyloid fibrils and for the biomimetic development of nanomaterials. The helical zinc oxide nanobelts simulations, focused on super elasticity, buckling, fracture, and the transfer of mechanical into electric energy, will produce a phenomenological Landau model useful for designing power nano-generators. The planned research is integrated with an educational program that facilitates the incorporation of nanomechanics into the engineering curriculum; it is also accompanied by efforts to encourage participation of underrepresented minorities. A cyber-module will illustrate for the Minnesota public underlying effects related to prion diseases, and mechanisms responsible for nano-energy storage. This module will be made available to the Minnesota Science Museum.

该奖项的研究目标是了解和模拟淀粉样原纤维的螺旋结构和力学，以及螺旋氧化锌纳米结构的稳定性和机械能存储。 由于这些结构的存在规模与原子间距离相当，因此原子细节对于理解它们的行为至关重要。计划中的纳米力学计算对于当前的量子方法来说是令人望而却步的，因为这些方法依赖于晶体固体的平移对称性。然而，通过新的客观分子动力学方法与自洽电荷密度函数紧束缚相结合，它们变得可能。这种耦合依赖于 Ewald 方法对螺旋电荷分布的拟议推广。初步结果表明这种推广是可行的，并且可以实现有效的纳米结构和生物分子模拟。 如果成功，该方法将首次能够定量评估现代材料和生命科学中螺旋结构上离散电荷分布产生的静电场。淀粉样原纤维研究旨在了解关键的原子细节、机械特性以及多态性和机械反应之间的相关性，将有助于阐明阿尔茨海默病和其他朊病毒疾病的分子机制。此外，它们还将对淀粉样原纤维的中尺度建模和纳米材料的仿生开发产生影响。螺旋氧化锌纳米带模拟侧重于超弹性、屈曲、断裂以及机械能到电能的转换，将产生可用于设计纳米功率发电机的唯象朗道模型。 计划中的研究与教育计划相结合，促进将纳米力学纳入工程课程；与此同时，还努力鼓励代表性不足的少数群体的参与。 网络模块将为明尼苏达州公众说明与朊病毒疾病相关的潜在影响以及负责纳米能量存储的机制。该模块将提供给明尼苏达科学博物馆。