Relativistic effects on the topology of the electron density
Relativistic effects on the topology of the electron density
复制标题
DOI：
10.1021/ct7001573
复制
发表时间：
2007-11-01
影响因子：
5.5
通讯作者：
Reiher, Markus
中科院分区：
文献类型：
--
作者：
Eickerling, Georg;Mastalerz, Remigius;Reiher, Markus
从X射线衍射实验或量子化学计算中获得的电子密度的拓扑分析提供了对原子和分子的电子结构的详细了解。特别令人感兴趣的是对含有(重)过渡金属元素的化合物的研究，这对实验和从量子化学的角度来说仍然是一个挑战。准确的计算需要明确考虑相对论效应。对价电子密度分布而言，这些效应往往只是通过相对论有效核势间接包含在内。但是，随着相对论哈密顿量的不同变体的发展，重元素的全电子计算与各种电子结构方法相结合是可行的。然而，对于用不同的相对论近似计算的总电子密度分布的拓扑学还没有系统的研究。因此，在这项工作中，我们从拓扑分析的角度比较了相对论哈密顿量对电子密度的影响。所选择的哈密顿量是四分量Dirac-Coulomb、准相对论二分量零级正则近似和标量相对论Douglas-Kroll-Hess算符。
The topological analysis of electron densities obtained either from X-ray diffraction experiments or from quantum chemical calculations provides detailed insight into the electronic structure of atoms and molecules. Of particular interest is the study of compounds containing (heavy) transition-metal elements, which is still a challenge for experiment as well as from a quantum-chemical point of view. Accurate calculations need to take relativistic effects into account explicitly. Regarding the valence electron density distribution, these effects are often only included indirectly through relativistic effective core potentials. But as different variants of relativistic Hamiltonians have been developed all-electron calculations of heavy elements in combination with various electronic structure methods are feasible. Yet, there exists no systematic study of the topology of the total electron density distribution calculated in different relativistic approximations. In this work we therefore compare relativistic Hamiltonians with respect to their effect on the electron density in terms of a topological analysis. The Hamiltonians chosen are the four-component Dirac-Coulomb, the quasi-relativistic two-component zeroth-order regular approximation, and the scalar-relativistic Douglas-Kroll-Hess operators.