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

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。研究的重点是进一步发展量子蒙特卡罗(QMC)方法及其在纳米系统中的应用。这项工作的一个重点是扩展QMC的能力，用于计算离子、激发态和光吸收上的Born-Oppenheimer力，即零点运动对轻原子系统激发的影响。PI将使用QMC和这些增强技术，来研究在科学发现和应用方面具有前景的分子纳米系统和簇。具体活动包括：确定作为分子器件原型正在探索的硫酸盐衍生物的电子结构，以及确定表现出超亮发光效应的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培训本科生和研究生先进的电子结构方法，以及在国家超级计算设施中有效使用并行和分布式计算平台。%这笔赠款支持计算方法的研究和教育，这些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量。PI计划开发现有方法的扩展，以实现对原子位置、电子激发态和光学吸收光谱的准确确定。这些增强的基于量子蒙特卡罗的工具将应用于原子和分子的特定纳米级结构，这些结构是基本感兴趣的，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.***