Many-Body Computational Methods for Electronic Structure of Cluster and Molecular Nanosystems

[01:26 . 68]该奖项支持对真实材料的电子和原子结构的多体计算方法的研究。研究重点是进一步发展量子蒙特卡罗（QMC）方法及其在纳米级系统中的应用。这项工作的一个重点是扩展QMC计算离子上的玻恩-奥本海默力、激发态和光吸收、零点运动对轻原子系统激发的影响的能力。PI将使用QMC和这些增强功能，研究具有科学发现和应用潜力的分子纳米系统和簇。具体活动包括：确定正在被探索作为分子器件原型的硫代衍生物的电子结构，确定具有超亮发光效应的SinHm和SinOlHm纳米晶体的光学和结构性质以及激发态。这项活动的一个重要方面是对本科生和研究生进行先进电子结构方法的培训，并在国家超级计算设施中有效地使用并行和分布式计算平台。该基金支持在计算方法方面的研究和教育，这些计算方法可以高精度地确定纳米结构中电子的量子态及其激发能。PI计划开发现有方法的扩展，以精确测定原子位置、电子激发态和光学吸收光谱。这些基于蒙特卡罗的增强量子工具将应用于原子和分子的特定纳米级结构，这些结构具有根本的兴趣，并可能对纳米电子学和其他新兴技术产生直接影响

0102668MitasThis award supports research on many-body computational approaches for electronic and atomic structures of real materials. Research focuses on further developing quantum Monte Carlo (QMC) methods and on their applications to nanoscale systems. One focus of the work is to expand the capabilities of QMC for calculations of Born-Oppenheimer forces on ions, excited states and optical absorption, the effects of zero point motion on excitations in systems with light atoms. The PI will use QMC together with these enhancements, to investigate molecular nanosystems and clusters with promising potential for scientific discoveries and applications. Specific activities include: determining the electronic structure of thiolate derivatives which are being explored as prototypes for molecular devices, and determining optical and structural properties, and excited states of SinHm and SinOlHm nanocrystals which exhibit ultrabright luminescence effects. An important aspect of this activity is the training of undergraduates and graduate students in advanced electronic structure methods and in efficient use of parallel and distributed computational platforms at national supercomputing facilities.%%%This grant supports research and education in computational methods that can determine the quantum states of electrons and their excitation energies in nanostructures to high accuracy. The PI plans to develop extensions of existing methods to enable the accurate determination of atomic positions, electronic excited states, and optical absorption spectra. These enhanced quantum Monte Carlo-based tools will be applied to specific nanoscale structures of atoms and molecules that are of fundamental interest and may have direct impact on nanoelectronics and other emerging technologies.***