ITR: Development of Computational Time-Dependent Density-Functional Theory Methods for the Study of Electronic Excitations in Correlated Materials

信息技术研究计划下的该奖项支持基础计算和理论研究，包括材料动力学相关性的算法开发。方法包括含时密度泛函理论（TDDFT）和Baym-Kadanoff守恒approximates.An这项工作的目的是建立一个新的计算方法之间的协同作用和洞察到非平凡的固态原型涉及绝缘体，过渡金属，稀土金属氧化物，过渡金属氧化物的动态电子关联。动态电荷密度和自旋密度响应函数将被计算;这些量直接映射到实验损失函数，并包含独特的相关签名。将采用含时优化势方法。这种方法，它依赖于一个表示的交换相关势作为一个功能的单电子轨道，是自相互作用自由。因此，它为相关材料的研究提供了一种很有前途的方法。“混合泛函”，这已被证明是成功的反铁磁绝缘体的基态的描述也将进行探讨。TDDFT也将在不调用线性响应机制的情况下实现，通过在实空间网格上显式求解依赖于时间的Kohn-Sham方程，在时间网格上传播状态。Baym-Kadanoff守恒近似也将被实现和探索。所提出的理论和计算将有助于现代计算材料物理学的研究生和博士后的教育。来自弱势背景的大学生将在夏季通过UTK的罗纳德麦克奈尔项目积极招募参与研究。该奖项是信息技术研究计划下的一个奖项，支持基础计算和理论研究，包括绝缘体、过渡金属、稀土金属氧化物和过渡金属氧化物中动态电子相关性的算法开发。这项工作涉及新的计算方法的发展和复杂的理论形式主义的探索，目的是建立一个定量的理论，电子动力学和运输的真实的材料。这项工作也将有助于理论指导，同时使用非弹性X射线散射材料的实验研究。虽然这是基础研究，但开发的计算方法可能会支持材料和光电器件技术的未来发展。

This award under the Information Technology Research initiative supports fundamental computational and theoretical research, including algorithm development, on dynamical correlations in materials. Methods to be explored include time-dependent density functional theory (TDDFT) and Baym-Kadanoff conserving approximations.An aim of this work is to establish a synergy between novel computational methods and insight into the dynamical electronic correlations in non-trivial solid-state archetypes involving insulators, transition metals, rare-earth metal hydrides, and transition-metal oxides. Dynamical charge-density and spin density response functions will be calculated; these quantities map directly into experimental loss functions, and contain unique signatures of correlation. The time-dependent optimized-potential method will be implemented. This method, which relies on a representation of the exchange-correlation potential as a functional of one-electron orbitals, is self-interaction free. So, it represents a promising approach for the study of correlated materials. "Hybrid functionals," which have proved successful in the description of the ground state of antiferromagnetic insulators will also be explored. TDDFT will also be implemented without invoking the linear-response regime, by explicitly solving the time-dependent Kohn-Sham equation on a real-space grid, propagating the states on a time grid. Baym-Kadanoff conserving approximations will also be implemented and explored.The proposed theoretical and computational will contribute to the education of graduate students and postdocs in modern computational materials physics. College students from disadvantaged backgrounds will be actively recruited for research participation during the summers through the Ronald McNair program at UTK. %%%This award under the Information Technology Research initiative supports fundamental computational and theoretical research, including algorithm development on dynamical electronic correlations in insulators, transition metals, rare-earth metal hydrides, and transition-metal oxides. The work involves the development of new computational methods and the exploration of sophisticated theoretical formalism with an aim to forge a quantitative theory of electron dynamics and transport in real materials. The work will also contribute theoretical guidance to concurrent experimental investigations of materials using inelastic x-ray scattering. While this is fundamental research, the computational methods developed may support future advances in materials and optoelectronic device technologies.***