On the dipolar electric field response of large systems
On the dipolar electric field response of large systems
复制标题
大系统的偶极电场响应
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
B. Kirtman
中科院分区：
文献类型：
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作者：
M. Springborg;B. Kirtman
然而，任何有限系统的偶极矩算子的定义，独立于其大小，是平凡的，它只是在过去的1- 20年中，表达式已被提出（基于独立粒子近似）的等效运营商的无限和周期性的系统。使用准一维系统作为一个例子，我们展示了如何不同版本的这些表达式可以推导出来，从而制定，第一次，一个多行列式处理的电子相关性的影响。基于另一个版本，建议完全依赖于已经可用的程序的MP2相关处理。与通常所假设的相反，我们证明了所谓的分支依赖于每单位的一个无限周期系统的偶极矩是直接相关的散装物理观测值，依赖于终端，即使对于样品的大小是远远高于热力学极限。特别是，静电场的结构响应的模型系统进行了研究。它示出了如何上的匡威压电系数的终端的效果可以计算和测量。此外，我们证明了有限场核弛豫处理的可行性，用于确定振动的贡献静态（超）极化率和动态非线性光学过程中的周期性系统。
Whereas the definition of the dipole moment operator for any finite system, independent of its size, is trivial, it is only within the last 1–2 decades that expressions have been proposed (based on the independent particle approximation) for the equivalent operator of an infinite and periodic system. Using a quasi-one-dimensional system as an example, we show how different versions of these expressions can be derived and thereby formulate, for the first time, a multi-determinant treatment of the effect of electron correlation. Based on another version, an MP2 correlation treatment is suggested that relies entirely on already available procedures. In contrast with what is often assumed, we demonstrate that the so-called branch dependence of the dipole moment per unit of an infinite periodic system is directly related to bulk physical observables that depend on the terminations even for samples of a size that is well above the thermodynamic limit. In particular, the structural response to an electrostatic field is studied for a model system. It is shown how the effect of the terminations on the converse piezoelectric coefficient can be calculated and measured. In addition, we demonstrate the viability of the finite field nuclear relaxation treatment for determining the vibrational contribution to static (hyper)polarizabilities and dynamic non-linear optical processes in periodic systems.