Density Functional Theory of Electronic Structure

基于Hohenberg-Kohn-Sham密度泛函理论的电子结构计算预测了哪些原子、分子和固体可以存在，以及具有哪些性质。这些预测的准确性取决于用于从电子密度构造能量的泛函或规则的准确性。这一理论研究的目标是：(1)从第一原理出发，建立更精确的局域自旋密度和广义梯度型交换关联和动能泛函，(2)将广义梯度近似应用于可测量性质的计算，如原子核处的电子自旋密度或金属表面的能量；(3)根据精确交换关联势的径向非定域性来理解这些近似的能力和局限性：(4)完善和检验完全非定域泛函，如自相互作用修正或加权密度近似；(5)构造局部赝势来描述金属中价电子与离子核之间的有效相互作用；(6)研究金属中的尺寸效应。理论研究将在目前用于确定原子、分子和固体性质的主要技术之一的基础上进行。这项工作的结果将加强密度泛函理论的基本原理，并为其计算实现提供新的方向指导。

Electronic structure calculations grounded in the Hohenberg-Kohn- Sham density functional theory predict what atoms, molecules, and solids can exist, and with what properties. The accuracy of these predictions depends on the accuracy of the functionals or rules used to construct the energy from the electron density. Goals of this theoretical research are: (1) to develop, from first principles, more accurate exchange correlation and kinetic energy functionals of the local spin density and generalized gradient types; (2) to apply generalized gradient approximations in calculations of measurable proerties such as the electron spin density at the nucleus of an atom or the energy of a metallic surface; (3) to understand the capabilities and limitations of these approximations in light of radical nonlocality of the exact exchange correlation potential; (4) to refine and test fully nonlocal functionals such as the self-interaction correction or the weighted density approximation; (5) to construct local pseudopotentials describing effective interactions between valence electrons and ionic cores in metals using only the equilibrium density, the valence, and a "smoothness" condition; (6) to study size effects in metals. %%% Theoretical research will be conducted on the foundations of one of the major techniques currently used to determine the properties of atoms, molecules and solids. The results of this work will reinforce the fundamentals of density functional theory and provide guidance for new directions for its computational implementation.