Lattice structure of mercury: Influence of electronic correlation
Lattice structure of mercury: Influence of electronic correlation
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DOI：
10.1103/physrevb.74.094102
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发表时间：
2006-09-01
影响因子：
3.7
通讯作者：
Stoll, Hermann
中科院分区：
文献类型：
--
作者：
Gaston, Nicola;Paulus, Beate;Stoll, Hermann
汞在233 K时凝结成角度为70.53度的菱面体结构。这种结构的理论预测是困难的。虽然Hartree-Fock处理根本不产生结合，但密度泛函理论（DFT）方法与梯度校正泛函预测了具有明显过大的晶格常数和约60度的正交角的结构，其对应于fcc结构。令人惊讶的是，使用简单的局域密度近似（LDA）的功能产生正确的结构和晶格常数非常好的协议与实验;相对论效应被证明是必不可少的达成这一协议。除了DFT结果，我们提出了一个基于波函数的汞的相关处理，并详细讨论了电子相关对汞的晶格参数，包括d壳层相关和三体项的影响，在原子间的相关能的多体分解。在耦合团簇水平上计算得到的晶格参数与实验值在1.5%以内。我们进一步提出的体积模量计算内的波函数的方法，并比较LDA和实验值。
Mercury condenses at 233 K into the rhombohedral structure with an angle of 70.53 degrees. Theoretical predictions of this structure are difficult. While a Hartree-Fock treatment yields no binding at all, density-functional theory (DFT) approaches with gradient-corrected functionals predict a structure with a significantly too large lattice constant and an orthorhombic angle of about 60 degrees, which corresponds to an fcc structure. Surprisingly, the use of the simple local density approximation (LDA) functional yields the correct structure and lattice constants in very good agreement with experiment; relativistic effects are shown to be essential for reaching this agreement. In addition to DFT results, we present a wave-function-based correlation treatment of mercury and discuss in detail the effects of electron correlation on the lattice parameters of mercury including d-shell correlation and the influence of three-body terms in the many-body decomposition of the interatomic correlation energy. The lattice parameters obtained with this scheme at the coupled cluster level of theory agree within 1.5% with the experimental values. We further present the bulk modulus calculated within the wave-function approach, and compare to LDA and experimental values.