Density-based partitioning methods for ground-state molecular calculations.
Density-based partitioning methods for ground-state molecular calculations.
复制标题
用于基态分子计算的基于密度的划分方法。
DOI：
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发表时间：
2014
影响因子：
2.9
通讯作者：
A. Wasserman
中科院分区：
文献类型：
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作者：
J. Nafziger;A. Wasserman
随着可以用现代电子结构方法处理的系统的日益复杂，开发准确有效的策略将系统划分为更小，更易处理的片段是至关重要的。我们回顾了一些最近提出的各种形式主义，以实现这一目标，使用碎片（基态）电子密度作为主要变量，重点是分区密度泛函理论（PDFT），作者一直在发展。为了揭示替代方法之间微妙但重要的差异，并强调密度分区所涉及的挑战，我们专注于最简单的系统，其中可以透明地比较各种方法。我们提供了基准PDFT计算homeodynamic双原子分子，并分析了相关的分区潜力。我们推导出一个新的确切条件，确定在核的分区电位的奇异性的强度，建立电荷转移和电负性均衡片段之间的连接，测试不同的方式处理分数片段的电荷和自旋，最后概述了一个一般的战略，克服离域和静态相关的密度泛函计算中的错误。
With the growing complexity of systems that can be treated with modern electronic-structure methods, it is critical to develop accurate and efficient strategies to partition the systems into smaller, more tractable fragments. We review some of the various recent formalisms that have been proposed to achieve this goal using fragment (ground-state) electron densities as the main variables, with an emphasis on partition density-functional theory (PDFT), which the authors have been developing. To expose the subtle but important differences between alternative approaches and to highlight the challenges involved with density partitioning, we focus on the simplest possible systems where the various methods can be transparently compared. We provide benchmark PDFT calculations on homonuclear diatomic molecules and analyze the associated partition potentials. We derive a new exact condition determining the strength of the singularities of the partition potentials at the nuclei, establish the connection between charge-transfer and electronegativity equalization between fragments, test different ways of dealing with fractional fragment charges and spins, and finally outline a general strategy for overcoming delocalization and static-correlation errors in density-functional calculations.