Non-collinear relativistic two-component X2C calculations of hyperfine couplings using local hybrid functionals. Importance of the high-density coordinate scaling limit.
Non-collinear relativistic two-component X2C calculations of hyperfine couplings using local hybrid functionals. Importance of the high-density coordinate scaling limit.
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DOI：
10.1021/acs.jctc.9b00911
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发表时间：
2019-12
影响因子：
5.5
通讯作者：
Artur Wodyński;M. Kaupp
中科院分区：
文献类型：
--
作者：
Artur Wodyński;M. Kaupp
局部混合泛函与位置相关的精确交换混合物已被实现在非共线的形式到一个两个组件的X2 C代码和评估的超精细耦合张量的一系列的3D，4D和5D过渡金属络合物。一个目的是观察局部杂化泛函是否有潜力改善核-壳和价-壳自旋极化之间的平衡，最近在3d复合物的非相对论计算中发现了这一点（Schattenberg，C.; Maier，T. M.; Kaupp，M. \n {\bf 2018}，\endash {14}，5653 -- 5672）可以扩展到重金属中心的超精细耦合。的两个组件的实施的正确性首先建立通过比较与以前的计算为3D系统有或没有显着的自旋轨道贡献，其超精细张量，和一个标准的"t-LMF“本地混合函数的良好性能得到确认。然而，当移动到4d和5d金属中心时，这种局部混合函数的性能恶化。这可能是由于它们违反了高密度极限下的齐次坐标标度条件，这对较重原子的核壳层特别重要。一个局部的混合功能，尊重这个高密度的限制，表现得更好的重金属中心。然而，它为3d系统带来了太高的精确交换混合物，并且太不灵活而不能同时在其他区域提供合理的化学精度。这些结果表明，目前需要开发改进的局部混合函数和局部混合泛函，这些泛函在由非常高和低得多的电子密度定义的不同空间区域中表现出有利的性质。
Local hybrid functionals with position-dependent exact-exchange admixture have been implemented in non-collinear form into a two-component X2C code and are evaluated for the hyperfine coupling tensors of a series of 3d, 4d, and 5d transition-metal complexes. One aim is to see if the potential of local hybrid functionals towards an improved balance between core-shell and valence-shell spin polarization, recently identified in nonrelativistic computations on 3d complexes (Schattenberg, C.; Maier, T. M.; Kaupp, M. \emph{J. Chem. Theory Comput.} {\bf 2018}, \emph{14}, 5653 -- 5672) can be extended to the hyperfine couplings of heavier metal centers. The correctness of the two-component implementation is first established by comparison to previous computations for 3d systems with or without notable spin-orbit contributions to their hyperfine tensors, and the good performance of a standard ``t-LMF'' local mixing function is confirmed. However, when moving to 4d and 5d metal centers, the performance of such local mixing functions deteriorates. This is likely due to their violation of the homogeneous coordinate scaling condition in the high-density limit, which is particularly important for the core shells of heavier atoms. A local mixing function that respects this high-density limit performs notably better for the heavier metal centers. However, it brings in much too high exact-exchange admixtures for the 3d systems and is too inflexible to simultaneously provide reasonable chemical accuracy in other areas. These results point to the ongoing need to develop improved local mixing functions and local hybrid functionals that exhibit favorable properties in different areas of space defined by very high and much lower electron densities.