ASYMPTOTIC PROPERTIES OF THE EXCHANGE ENERGY DENSITY AND THE EXCHANGE POTENTIAL OF FINITE SYSTEMS - RELEVANCE FOR GENERALIZED GRADIENT APPROXIMATIONS
ASYMPTOTIC PROPERTIES OF THE EXCHANGE ENERGY DENSITY AND THE EXCHANGE POTENTIAL OF FINITE SYSTEMS - RELEVANCE FOR GENERALIZED GRADIENT APPROXIMATIONS
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DOI：
10.1007/bf01436696
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发表时间：
1992-04-01
期刊：
影响因子：
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通讯作者：
VOSKO, SH
中科院分区：
文献类型：
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作者：
ENGEL, E;CHEVARY, JA;VOSKO, SH
结果表明，仅用于交换的广义梯度近似（GGA）由于其形式非常有限，通常不能同时再现有限系统的交换能量密度和交换势的渐近形式。此外，使 GGA 形式上接近这些渐近形式中的至少一种的机制不会提高原子渐近状态相关部分中的相应数量。通过构建与迄今为止所有 GGA 相比具有优异原子交换能量但不再现精确交换能量密度的渐近形式的 GGA，证明了该属性对于获得极其精确的原子交换能量并不重要。我们得出的结论是，GGA 就其概念而言并不适合重现有限系统的这些渐近性质。作为我们讨论的副产品，我们提出了一个特别简单和直接的证明，证明有限球形系统交换势的众所周知的渐近结构。
It is shown that generalized gradient approximations (GGAs) for exchange only, due to their very limited form, quite generally can not simultaneously reproduce both the asymptotic forms of the exchange energy density and the exchange potential of finite systems. Furthermore, mechanisms making GGAs formally approach at least one of these asymptotic forms do not improve the corresponding quantity in the relevant part of the asymptotic regime of atoms. By constructing a GGA which leads to superior atomic exchange energies compared to all GGAs heretofore but does not reproduce the asymptotic form of the exact exchange energy density it is demonstrated that this property is not important for obtaining extremely accurate atomic exchange energies. We conclude that GGAs by their very concept are not suited to reproduce these asymptotic properties of finite systems. As a byproduct of our discussion we present a particularly simple and direct proof of the well known asymptotic structure of the exchange potential of finite spherical systems.