CAREER: Novel Green's function methods for predicting experimentally relevant quantities for solids and molecules

职业：Novel Green 函数方法用于预测固体和分子的实验相关量

• 批准号: 1453894
• 负责人: Dominika Zgid
• 金额: $ 63.64万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-12-01 至 2022-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1453894&HistoricalAwards=false
• 关键词: CAREER; Novel; Green; function; methods

Dominika Zgid, of the University of Michigan, is supported by an award from the Chemical Theory, Models and Computational Methods program in the Chemistry Division to develop new computational tools to study large molecules and solids in which the correlated motion of electrons is very important. In modern science and technology, materials chemistry plays an big role in the production of advanced optoelectronic materials, semiconductors and superconductors, solar cell and battery materials. To enable the discovery of new materials and to answer experimental questions, theory has to predict experimentally relevant, measurable quantities. In the last fifty years, the majority of quantum chemistry research was focused on the development of methodological advances for molecular systems. Currently molecular problems can be described very accurately. However, for large strongly correlated molecules and solids, quantum chemistry still lacks computational tools that describe electronic correlation accurately in a systematically improvable manner and deliver experimentally useful predictions. The development of novel ab-initio theoretical methods that are at the interface of quantum chemistry and condensed matter physics and are capable of delivering useful experimental predictions for solids is the major aim of this research. This interdisciplinary project involves training and mentoring of graduate students and postdocs by allowing them to understand their research in the broadest possible sense. The research prepares them for a wide range of careers. Dr. Zgid is also actively engaged in public outreach for minorities in Science, Technology, Education and Mathematics (STEM) by organizing workshops for middle school girls. The Green's function language provides a natural link to experiment, since spectra can be readily calculated without the cumbersome excited state formalism present in wave function or density theories. Green's function methods are controlled, reliable, and systematically improvable and may easily be generalized by employing embedding methods to work for solids or large molecules. In order to calculate excitation spectra, this project implements the Bethe-Salpeter equation with a second order Green's function method and self-energy embedding approaches. The formalism is calibrated on small molecules and subsequently extended to solids by using embedding methods. Since the realism and predictive power of quantum mechanical simulations depend on the accuracy of modelling all electrons, significant attention is given to the investigation of effective Hamiltonian approaches that aim to make Green's function embedding methods quantitative for realistic molecular and crystalline systems. Finally, since the Green's function is a large object that can be calculated in parallel, the investigation focuses on efficient ways of expressing Green's functions in computer implementations. A major outcome of the project is software containing efficient, reliable and systematically improvable Green's function embedding methods for solids that is released to the public. Additionally, Dr. Zgid's research group is preparing a series of lecture notes for graduate students explaining Green's functions in order to reduce the language barrier frequently experienced by quantum chemists when working with the Green's function formalism. The proposed interdisciplinary research involves training and mentoring of graduate students and postdocs allowing them to understand their research in the broadest possible sense and prepares them for wide range of careers. Additionally, Dr. Zgid also takes part in the "Science for tomorrow" program for middle school students from underserved communities in Michigan.

密歇根大学的Dominika Zgid得到了化学部化学理论、模型和计算方法项目的支持，他开发了新的计算工具来研究大分子和固体，其中电子的相关运动非常重要。在现代科学技术中，材料化学在先进光电子材料、半导体和超导体、太阳能电池和电池材料的生产中发挥着重要作用。为了能够发现新材料并回答实验问题，理论必须预测与实验相关的、可测量的数量。在过去的五十年里，量子化学的大部分研究都集中在分子体系方法学的发展上。目前，分子问题可以非常准确地描述。然而，对于大的强关联分子和固体，量子化学仍然缺乏以系统可改进的方式准确描述电子关联并提供实验上有用的预测的计算工具。发展新的处于量子化学和凝聚态物理交界处的从头算理论方法，并能够提供有用的固体实验预测是这项研究的主要目的。这个跨学科的项目包括对研究生和博士后的培训和指导，让他们尽可能广泛地了解自己的研究。这项研究让他们为广泛的职业生涯做好了准备。Zgid博士还通过为中学女生组织讲习班，积极参与科学、技术、教育和数学(STEM)领域少数群体的公共宣传。格林函数语言提供了与实验的自然联系，因为可以很容易地计算光谱，而不需要波函数或密度理论中存在的繁琐的激发态形式。格林函数方法是可控制的、可靠的、系统可改进的，并且可以很容易地通过使用嵌入方法来推广到固体或大分子。为了计算激发光谱，本项目用二阶格林函数方法和自能嵌入方法实现了Bethe-Salpeter方程。该公式在小分子上进行了校准，然后通过使用嵌入方法扩展到固体上。由于量子力学模拟的真实性和预测能力取决于模拟所有电子的准确性，因此人们非常关注有效的哈密顿方法的研究，目的是使格林函数嵌入方法对现实的分子和晶体系统进行量化。最后，由于格林函数是一个可以并行计算的大对象，因此研究的重点是在计算机实现中表示格林函数的有效方法。该项目的一个主要成果是向公众发布了包含高效、可靠和可系统改进的固体格林函数嵌入方法的软件。此外，Zgid博士的研究小组正在为研究生准备一系列讲解格林函数的课堂讲稿，以减少量子化学家在使用格林函数形式主义时经常遇到的语言障碍。拟议的跨学科研究涉及对研究生和博士后的培训和指导，使他们能够尽可能广泛地了解自己的研究，并为广泛的职业生涯做好准备。此外，兹吉德博士还参加了为密歇根州医疗服务不足社区的中学生举办的“明天的科学”项目。