Systematic approach to Density Functional Theory

加州大学欧文分校的Kieron Burke获得了化学理论，模型和计算方法计划的奖励，以开发提高电子结构计算准确性和可靠性的方法。现代化学和材料研究越来越依赖于电子结构计算，即，解决量子力学方程的电子预测或理解物理和化学性质。 伯克的方法使用量子力学的非常基本的性质，以一种高度系统化的方式导出改进的近似。 其智力价值是比以前更深入地理解电子的量子本质，从而显着减少错误。其影响可能是巨大的，因为它可以改善每年数千篇科学论文的电子结构计算，包括与药物发现有关的论文，以及新催化剂的识别和物质的新阶段。 伯克和他的研究小组联合收割机结合了三个不同学科的理论方法。一个系统的非经验的密度泛函近似方法，通过普朗克常数的幂的渐近展开，确定量子效应的强度的基本量。对于模型系统，可以显式地找到近似值，并产生比以前的公式更精确的结果。对于现实系统（分子和材料），一般形式可以用来推导渐近精确的近似，显着改善那些在今天使用的，并限制更复杂的方法。这些方法也适用于无轨道电子结构计算的问题，这有希望使更大的距离和时间尺度的密度泛函理论（DFT）计算。这项工作包括一个替代战略的DFT框架在今天使用，所谓的潜在功能理论。一个自然的联系与热DFT有可能导致有用的应用程序中的含时密度泛函理论的分子和温暖的致密物质。

Kieron Burke of the University of California-Irvine is supported by an award from the Chemical Theory, Models and Computational Methods program to develop methods that improve the accuracy and reliability of electronic structure calculations. Modern chemical and materials research increasingly relies on electronic structure calculations, i.e., solving the equations of quantum mechanics for electrons to predict or understand physical and chemical properties. Burke's method uses very fundamental properties of quantum mechanics to derive improved approximations in a highly systematic fashion. The intellectual value is to understand the quantum nature of electrons more deeply than before, in a way that significantly reduces errors. The impact could be significant, as it could improve electronic structure calculations for thousands of scientific papers each year, including those related to drug discovery, and to the identification of new catalysts, and new phases of matter. There is also a broad-based educational component, as graduate, undergraduate, and high school students are involved in the research.Burke and his research group combine theoretical methods from three different disciplines. A systematic non-empirical approach to density functional approximation is used, via an asymptotic expansion in powers of Planck's constant, the fundamental quantity that determines the strength of quantum effects. For model systems, the approximations can be found explicitly, and yield far more accurate results than previous formulas. For realistic systems (molecules and materials), the general forms can be used to deduce asymptotically exact approximations that significantly improve on those in use today, and constrain more sophisticated approaches. The methods are also applied to the problem of orbital-free electronic structure calculations, which holds the promise of making much larger distance and time scales accessible to density functional theory (DFT) calculations. The work includes an alternative strategy to the DFT framework in use today, called potential functional theory. A natural connection with thermal DFT has the potential to lead to useful applications in the time-dependent density functional theory of molecules and of warm dense matter.