Tuning Reactivity, Electronic Structure and Properties via Pressure: Predicting Novel Superconductors

通过压力调节反应性、电子结构和特性：预测新型超导体

• 批准号: 1505817
• 负责人: Eva Zurek
• 金额: $ 34.5万
• 依托单位: SUNY at Buffalo
• 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: 2015-06-15 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1505817&HistoricalAwards=false
• 关键词: Tuning; Reactivity; Electronic; Structure; Properties

NON-TECHNICAL SUMMARYThis award supports research and education whose ultimate goal is to rationally design new superconductors, materials through which electric current can flow without losing energy, via computational modeling. Replacing copper wires with superconducting power lines would have a tremendous impact on the electrical power infrastructure of the USA, but unfortunately all of the currently known superconductors must be cooled down to very low temperatures before they become superconducting. Research suggests that hydrogen-rich solids could potentially behave as superconductors at high temperatures, and they will therefore be the focus of this project.Just like diamond can be synthesized at high pressure within the earth, researchers can use pressure as a variable to create new materials with unusual properties that may remain stable when the pressure is released. A number of new superconductors have been synthesized in this way. However, since these experiments are very difficult to perform, computational predictions can accelerate new materials discovery. The PI will carry out calculations based upon quantum mechanics to predict promising new targets for synthesis, and collaborate with leading experimental groups in high-pressure research that will attempt to synthesize these materials. To advance this goal the PI will further develop a set of software tools, which can be used to computationally predict the structure of a solid without any experimental information. These tools are made freely available to the materials science, physics and chemistry communities, thereby advancing rational materials design as well as current and future discoveries in science and engineering. Graduate and undergraduate students will be trained in rational computational materials design and programming, thereby preparing them for future careers where synergy between theory, computation and experiment leads to innovation. Student and faculty exchange with a primarily undergraduate, minority serving institution (California State University San Bernardino) will expose these students to research and future career opportunities in STEM fields, and train them in state-of-the-art materials modeling techniques. TECHNICAL SUMMARYThis award supports theoretical research and education that will lead towards the rational design of novel superconductors. The PI will computationally predict the crystal structures of materials with unique stoichiometries and structures that can be synthesized using the pressure variable, and study their electronic structures and properties via first-principles calculations. Focus will be placed on compounds containing hydrogen doped with a p-block element because strong covalent bonds between the p-block atoms may render these structures metastable upon decompression to atmospheric pressures, and both experiment and theory suggest that binary hydrides may have a high superconducting transition temperature. The PI will also study binary polar intermetallics, as it has already been demonstrated that many of these can be synthesized at modest pressures, remain stable at atmospheric conditions, and behave as BCS superconductors. New, perhaps completely unexpected, chemistry and totally new types of materials will be discovered theoretically, and the predictions will be confirmed by leading experimental groups in high pressure research. The award will also support the further development of the "XtalOpt" evolutionary algorithm, which can be used to predict the structure of an extended system given only its stoichiometry. Key developments will increase the size and complexity of the unit cells that can be predicted without any experimental information, and accelerate the progress of a priori structure prediction for extended systems. The crystallography suite within the highly popular chemical builder, editor and visualizer "Avogadro", will be further advanced. Because XtalOpt and Avogadro are written under licenses approved by the Open Source Initiative, the program code can be re-used, thereby contributing towards cyberinfrastructure as well as current and future discoveries in science and engineering. Graduate and undergraduate students will be trained in rational computational materials design and programming, thereby preparing them for future careers where synergy between theory, computation and experiment leads to innovation. Student and faculty exchange with a primarily undergraduate, minority serving institution (California State University San Bernardino) will expose these students to research and future career opportunities in STEM fields, and train them in state-of-the-art materials modeling techniques.

非技术总结该奖项支持研究和教育，这些研究和教育的最终目标是通过计算建模合理地设计新的超导体，这种材料可以使电流流过而不损失能量。用超导输电线取代铜线将对美国的电力基础设施产生巨大影响，但不幸的是，所有目前已知的超导体在成为超导之前都必须冷却到非常低的温度。研究表明，富含氢的固体可能在高温下表现为超导体，因此它们将成为该项目的重点。就像钻石可以在地球内部的高压下合成一样，研究人员可以利用压力作为变量来创造具有特殊性质的新材料，这些材料在压力释放时可能保持稳定。用这种方法已经合成了许多新的超导体。然而，由于这些实验很难进行，计算预测可以加速新材料的发现。PI将进行基于量子力学的计算，以预测有前景的新合成目标，并与领先的实验小组合作进行高压研究，试图合成这些材料。为了推进这一目标，PI将进一步开发一套软件工具，这些工具可以在没有任何实验信息的情况下通过计算预测固体的结构。这些工具向材料科学、物理学和化学界免费提供，从而促进合理的材料设计以及当前和未来的科学和工程发现。研究生和本科生将接受合理的计算材料设计和编程方面的培训，从而为未来的职业生涯做好准备，理论、计算和实验之间的协同作用将导致创新。学生和教师与主要为少数族裔服务的本科院校(加州州立大学圣贝纳迪诺分校)进行交流，将使这些学生接触到STEM领域的研究和未来的职业机会，并对他们进行最先进的材料建模技术培训。技术总结该奖项支持理论研究和教育，这些研究和教育将导致新型超导体的合理设计。PI将通过计算预测具有独特化学计量比的材料的晶体结构，以及可以使用压力变量合成的结构，并通过第一性原理计算研究其电子结构和性质。重点将放在含有掺有p-块元素的氢的化合物上，因为p-块原子之间的强烈共价键可能会使这些结构在减压到大气压下变得亚稳，而且实验和理论都表明，二元氢化物可能具有较高的超导转变温度。PI还将研究二元极性金属间化合物，因为已经证明其中许多可以在中等压力下合成，在大气条件下保持稳定，并表现为BCS超导体。理论上将发现新的、也许完全出乎意料的化学和全新类型的材料，这些预测将得到高压研究中领先的实验小组的证实。该奖项还将支持“XtalOpt”进化算法的进一步发展，该算法仅在给定化学计量比的情况下就可以用来预测扩展系统的结构。关键的发展将增加在没有任何实验信息的情况下可以预测的单胞的大小和复杂性，并加速扩展系统的先验结构预测的进展。非常受欢迎的化学建造器、编辑者和可视化工具“Avogadro”中的结晶学套件将进一步推进。由于XtalOpt和Avogadro是在开放源码倡议批准的许可证下编写的，因此程序代码可以重复使用，从而为网络基础设施以及当前和未来的科学和工程发现做出贡献。研究生和本科生将接受合理的计算材料设计和编程方面的培训，从而为未来的职业生涯做好准备，理论、计算和实验之间的协同作用将导致创新。学生和教师与主要为少数族裔服务的本科院校(加州州立大学圣贝纳迪诺分校)进行交流，将使这些学生接触到STEM领域的研究和未来的职业机会，并对他们进行最先进的材料建模技术培训。