Correlation energy of a two-dimensional electron gas from static and dynamic exchange-correlation kernels
Correlation energy of a two-dimensional electron gas from static and dynamic exchange-correlation kernels
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DOI：
10.1103/physrevb.68.235116
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发表时间：
2003-07
影响因子：
3.7
通讯作者：
R. Asgari;M. Polini;B. Davoudi;M. Tosi
中科院分区：
文献类型：
--
作者：
R. Asgari;M. Polini;B. Davoudi;M. Tosi
我们使用进入系统线性介电响应的交换相关核 fxc(q,!) 的几种可用近似值来计算二维均质电子气的相关能。正如 Lein 等人之前的工作一样。 [物理。 Rev. B 67, 13431 (2000)]关于三维电子气，我们关注核的波数和频率依赖性的相对作用，并根据（q，i！）平面的贡献分析相关能量。我们发现核与电子对分布函数的一致性很重要，在这种情况下，就相关能量而言，核在时间上的非局域性并不重要。我们还表明并解释了为什么流行的绝热局部密度近似在二维情况下比在三维情况下表现更好。
We calculate the correlation energy of a two-dimensional homogeneous electron gas using several available approximations for the exchange-correlation kernel fxc(q, !) entering the linear dielectric response of the system. As in the previous work of Lein et al. [Phys. Rev. B 67, 13431 (2000)] on the three-dimensional electron gas, we give attention to the relative roles of the wave number and frequency dependence of the kernel and analyze the correlation energy in terms of contributions from the (q, i!) plane. We find that consistency of the kernel with the electron-pair distribution function is important and in this case the nonlocality of the kernel in time is of minor importance, as far as the correlation energy is concerned. We also show that, and explain why, the popular Adiabatic Local Density Approximation performs much better in the two-dimensional case than in the three-dimensional one.