Density Functional Theory of Electronic Structure

9521353 Perdew该基金用于支持原子、分子和固体电子结构的理论研究。 研究的目的是通过以下几个方面改进密度泛函和赝势理论的方法和概念：（1）电子周围的交换关联空穴描述了电子保持分离的趋势，它在一定程度上可以从一个系统转移到另一个系统。 对于密度均匀的电子气，空穴将通过自旋和电子间的空间分离来分析。(2)对于OnormalO系统中局域自旋密度和广义梯度近似的成功，给出了一个Oon-top holeO解释。 原子和分子中精确或接近精确的空穴将被用来检验这些近似的优点和缺点。(3)系统的局部自旋密度和广义梯度近似计算将进行元素固体。 局域自旋密度和广义梯度近似能将通过约化密度梯度进行分析。 (4)为了完成带电金属团簇的液滴模型，将评估电离能的尺寸效应的量子贡献。 (5)结合简单性和现实性，从固态电子密度构建了局域电子-离子赝势。测试和应用将包括计算压力下简单金属的声子频率和OuniversalO相图。(6)在追求化学的准确性，O混合方法将开发相结合的密度泛函的短程相关性与波函数方法的长程。(7)密度梯度膨胀的动能将被测试和收敛性图解，导致一个简单的Oorder-NO方法的电子结构计算。 数值和分析技术将用于开发，测试和应用新方法来计算原子，分子，特别是固体的电子结构的特性。 这项工作的结果可能会对使用这些方法计算与电子结构相关的各种材料特性的研究人员产生广泛的影响。 ***

9521353 Perdew This grant is being made to support theoretical research on the electronic structure of atoms, molecules and solids. The goal of the research is to improve methods and concepts of the density functional and pseudopotential theories through the following projects: (1) The exchange-correlation hole around an electron, describing the tendency of electrons to stay apart, is somewhat transferable from one system to another. For an electron gas of uniform density, the hole will be analyzed by spin and by interelectronic spatial separation. (2) An Oon-top holeO explanation will be given for the success of the local spin density and generalized gradient approximations in OnormalO systems. Exact or nearly exact holes in atoms and molecules will be used to test the strengths and weaknesses of these approximations. (3) Systematic local spin density and genralized gradient approximation calculations will be undertaken for the elemental solids. Local spin density and generalized gradient approximation energies will be analyzed by reduced density gradients. (4) To complete the liquid drop model for a charged metallic cluster, the quantum contribution to the size effect for the ionization energy will be evaluated. (5) A local electron-ion pseudopotential, combining simplicity with realism, has been constructed from solid state electron densities, Tests and applications will include calculation of phonon frequencies and OuniversalO phase diagrams for simple metals under pressure. (6) In a quest for Ochemical accuracy,O hybrid methods will be developed by combining density functionals for short-range correlations with wavefunction methods for long-range. (7) The density gradient expansion of the kinetic energy will be tested and convergently resummed, leading to a simple Oorder-NO method of electronic structure calculation. %%% Numerical and analytical techniques will be used to develop, test and apply new methods to calculate the properties of the electr onic structure of atoms, molecules and particularly, solids. The results of this work could have a wide-ranging impact on researchers using these methods to calculate a wide variety of material properties related to the electronic structure. ***