Fitting of local densities in periodic systems
Fitting of local densities in periodic systems
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DOI：
10.1103/physrevb.78.073102
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发表时间：
2008-08-01
影响因子：
3.7
通讯作者：
Usvyat, Denis
中科院分区：
文献类型：
--
作者：
Maschio, Lorenzo;Usvyat, Denis
我们提出了一种密度拟合的形式，这是分子背景下广泛使用的方法，用于近似周期系统中局部密度之间的电子斥力积分。通过将拟合分离为倒易空间部分（使用扩展但无矩的拟合基组）和直接空间部分（使用一组小的、局部的通常高斯型轨道）来实现有效的处理。该方法可以应用于周期性Hartree-Fock、Kohn-Sham、post-Hartree-Fock 相关等方法。我们证明了该方法在二阶周期性局部 Moller-Plesset 微扰理论中的效率，这在传统的公式中对于晶体来说非常昂贵。
We present a formalism for density fitting, a widely used method in molecular context, to approximate the electron repulsion integrals between local densities in periodic systems. An efficient treatment is achieved through a separation of the fitting into a reciprocal space part, done with an extended, but momentless fitting basis set, and a direct space part with a small, local set of usual Gaussian-type orbitals. This approach can be applied to periodic Hartree-Fock, Kohn-Sham, post-Hartree-Fock correlation, etc. methods. We demonstrate the efficiency of the method in the periodic local Moller-Plesset perturbation theory of the second order, which in the conventional formulation is for crystals very expensive.