Approximation of the exchange-correlation Kohn-Sham potential with a statistical average of different orbital model potentials
Approximation of the exchange-correlation Kohn-Sham potential with a statistical average of different orbital model potentials
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DOI：
10.1016/s0009-2614(99)00128-1
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发表时间：
1999-03-19
影响因子：
2.8
通讯作者：
Baerends, EJ
中科院分区：
文献类型：
--
作者：
Gritsenko, OV;Schipper, PRT;Baerends, EJ
利用模型势Kohn-Sham势v（xc sigma）的统计平均值，提出了不同模型轨道势的统计平均值，作为交换相关性的一种建模方法。利用模型势y(xc sigma)（Ei）的统计平均值，得到了具有适当原子壳层结构的KS轨道最高已占轨道psi（N sigma）和其他已占轨道模型势v(xc)（GLB）的精确渐近近似势v(xc sigma)（SAOP）。为了获得精确的渐近性，在v(xc sigma)（Ei）内使用无量纲梯度参数x（sigma）的指数积分函数E-1（l/x(sigma)）。对于Ne原子，用新模型势计算，原则上可以完美地再现所有的能量特征(轨道能量和维里积分I-v= Sigma（Sigma）积分[3 rho(Sigma)(r) + r]。（∑）(r)]v（xc∑)(r)dr）对于一个特定的系统本质上精确的v（xc∑）以及v（xc∑）在内外区域的斜率。用v(xc sigma)（SAOP）进行的原子计算表明，该模型既能很好地计算出psi（N sigma）的能量E-N sigma，也能很好地计算出维里积分。(C) 1999 Elsevier Science B.V.版权所有
A statistical average of different model orbital potentials is proposed as a way to model the exchange-correlation is developed using the statistical average of a model potential Kohn-Sham potential v(xc sigma). An approximate potential v(xc sigma)(SAOP) is developed using the statistical average of a model potential y(xc sigma)(Ei) With exact asymptotics for the highest occupied KS orbital psi(N sigma) with a model potential v(xc)(GLB) for other occupied orbitals, which has a proper atomic shell structure. To get exact asymptotics, an exponential integral function E-1(l/x(sigma)) of the dimensionless gradient argument x(sigma) is employed within v(xc sigma)(Ei). For the Ne atom calculations with the new model potential can, in principle, reproduce perfectly all energy characteristics (orbital energies and the virial integral I-v= Sigma(sigma) integral[3 rho(sigma)(r) + r . del rho(sigma)(r)]v(xc sigma)(r)dr) of the essentially accurate v(xc sigma) for a particular system, as well as the slopes of v(xc sigma) in both outer and inner regions. Atomic calculations with v(xc sigma)(SAOP) show that this model gives a good quality of both the calculated energy E-N sigma of psi(N sigma) and of the calculated virial integral. (C) 1999 Elsevier Science B.V. All rights reserved.