CAREER: Developing Quantum Nanogeochemistry for Molecular Studies and Inclusive Education

美国国家科学基金会化学部的环境化学科学计划支持爱荷华大学Sara E.Mason教授的研究，他将指导一个最终目标是将量子纳米地球化学作为平台的项目，(1)提供对环境纳米颗粒(ENP)结构-反应性的基本了解，(2)融合ENP反应性的不同理论，以及(3)招收社区学院(CC)学生，以便在大学层面提供培训机会。研究策略是基于密度泛函理论(DFT)对两类ENPs进行模拟：水溶液氢氧化铝(GAP)模型和矿泉水界面模型(PSM)。确定了适合每个模型类别的反应性问题，并通过比较设计了系统的模拟实验，以分离控制反应性的因素。这些项目旨在将GAP和PSM的原子模拟结果发展成ENP反应性的新概念模型，这一目标将支持或消除现有理论。为此，将利用模型之间的区别，例如，间隙是跟踪轨道相互作用反应性的理想模型，因为它们是真正的纳米颗粒，预计参与界面键合的电子态更少。此外，这些氢氧化铝没有d电子，因此它们的电子结构没有类似结构的氢氧化铁那么复杂。同时，PSM几何结构是探索吸附诱导的长程键弛豫和相关能量如何在键价(BV)框架中被捕获的理想方法。其中几个拟议的模拟将涉及首次计算，例如后来描述的DFT Cosmo(类传导屏蔽模型)(Delta)H2O(部分显式水合)方法，用于模拟Al30(GAP)水溶液，并推导表面特定Hubbard U校正以精确模拟由强关联矿物氧化物组成的PSM。拟议的工作将使人们能够改进对水中污染物的隔离的预测，这最终可能导致新的水修复战略。每个研究项目将支持研究生和本科生的培训，重点将放在“永远不会太迟学习”(NTLL)计划及其使命上，即让社区学院的学生参与教育和研究活动，以扩大将他们培养为下一代科学家的机会。努力将研究成果组织到DFT数据库中，并将其报告在相关的数据管理计划中，确保从原子模拟获得的基本信息将传播给研究界，无论提议的概念模型是否失败。统一的研究和教育计划与主要研究人员的优势、背景和致力于发展量子纳米地球化学作为环境化学科学中的一个重要领域相适应。

The Environmental Chemical Sciences Program in the Chemistry Division at the National Science Foundation supports the research of Professor Sara E. Mason at the University of Iowa who will direct a project whose ultimate goal is to develop quantum nanogeochemistry as a platform, (1) to provide fundamental understanding of environmental nanoparticle (ENP) structure-reactivity, (2) to merge distinct theories of ENP reactivity, and, (3) to recruit community college (CC) students for training opportunities at the university level. The research strategy is to carry out Density Functional Theory (DFT)-based simulations on two classes of ENPs: Aqueous aluminum hydroxides modeled as Giant Aluminum Polycations (GAPs) and mineral-water interfaces modeled as Periodic Slab Models (PSMs). Reactivity questions that are suited to each model category are identified, and systematic simulation experiments are designed using comparisons to isolate what controls reactivity. The projects are designed to develop atomistic simulations results of both GAPs and PSMs into new conceptual models for ENP reactivity, a goal that will support or dispel existing theories. For this purpose, the distinctions between the models will be exploited, for example, GAPs are ideal models for tracking reactivity with orbital interactions because they are truly nanoparticulate, and fewer electronic states are expected to participate in interfacial bonding. Also, these aluminum hydroxides do not have d electrons, so they have a less complicated electronic structure than similarly structured iron hydroxides. Meanwhile, the PSM geometry is ideal for probing how adsorption-induced long range bond relaxation and relative energetics can be captured in a Bond Valence (BV) framework. Several of the proposed simulations will involve first time calculations, such as the later described DFT + COSMO (conduction-like screening model)+ (delta)H2O (partial explicit hydration) method for simulating the aqueous Al30 (GAP) and deriving surface-specific Hubbard U corrections to accurately model PSMs comprised of strongly correlated mineral oxides. The proposed work will enable improved predictions about the sequestration of aqueous contaminants that could ultimately lead to new water remediation strategies. Each research project will support the training of graduate and undergraduate students, and a major emphasis will be placed on the "Never Too Late to Learn" (NTLL) program and its mission to engage community college students in education and research activities that will extend opportunities to train them as the next generation scientists. Efforts to organize research outcomes into DFT databases that will be reported in the associated Data Management Plan, ensure that the fundamental information obtained from the atomistic simulations will be disseminated to the research community, regardless of any failure to pioneer the proposed conceptual models. The unified research and education plans are suited to principal investigator's strengths, background, and commitment to develop quantum nanogeochemistry as a vital field in environmental chemical science.