Local Hamiltonians for quantitative Green's function embedding methods.
Local Hamiltonians for quantitative Green's function embedding methods.
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用于定量格林函数嵌入方法的局部哈密顿量。
DOI：
10.1063/1.4901432
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
D. Zgid
中科院分区：
文献类型：
--
作者：
A. Rusakov;J. Phillips;D. Zgid
为大分子和实际固体寻找Schrödinger方程近似解的嵌入计算通常分三步进行，包括(i)构建具有近似初始实际系统的低能物理的有效相互作用的模型系统，（ii）将模型系统映射到杂质哈密顿量上，以及（iii）解决杂质问题。我们开发了一种新的参数化杂质哈密顿量的方法，避免了构造低能模型系统的数学上不受控制的步骤。相反，杂质哈密顿量立即被参数化，以恢复现实系统在高频或短时间极限下的自能。参数化虚拟杂质哈密顿量的有效相互作用是嵌入区域的局部相互作用，并且隐式地包含了原始现实哈密顿量中存在的所有非局部相互作用。我们证明了这个杂质哈密顿量可以得到很好的总能量和自能量，它们很好地近似于初始现实系统的量。此外，我们还表明，只要设计有效的杂质哈密顿参数来恢复高频率初始现实系统的自能，我们就可以期望得到良好的总能量和自能。最后，我们提出了两种实用的方法来评估参数化杂质模型的有效积分。
Embedding calculations that find approximate solutions to the Schrödinger equation for large molecules and realistic solids are performed commonly in a three step procedure involving (i) construction of a model system with effective interactions approximating the low energy physics of the initial realistic system, (ii) mapping the model system onto an impurity Hamiltonian, and (iii) solving the impurity problem. We have developed a novel procedure for parametrizing the impurity Hamiltonian that avoids the mathematically uncontrolled step of constructing the low energy model system. Instead, the impurity Hamiltonian is immediately parametrized to recover the self-energy of the realistic system in the limit of high frequencies or short time. The effective interactions parametrizing the fictitious impurity Hamiltonian are local to the embedded regions, and include all the non-local interactions present in the original realistic Hamiltonian in an implicit way. We show that this impurity Hamiltonian can lead to excellent total energies and self-energies that approximate the quantities of the initial realistic system very well. Moreover, we show that as long as the effective impurity Hamiltonian parametrization is designed to recover the self-energy of the initial realistic system for high frequencies, we can expect a good total energy and self-energy. Finally, we propose two practical ways of evaluating effective integrals for parametrizing impurity models.
影响因子：
44.1
作者：
Gull, Emanuel;Millis, Andrew J.;Werner, Philipp
通讯作者：
Werner, Philipp