Hlinčík Andrej, Fülöp Tadeáš, Herich Peter, Kožíšek Jozef, Lušpai Karol, Bučinský Lukáš
Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic.
IUCrJ. 2025 Jul 1;12(Pt 4):444-461. doi: 10.1107/S2052252525003355.
In this study, the flexibility of the multipole Hansen-Coppens (HC) model refinement is investigated on calculated structure factors from a DFT reference for the tetrakis(μ-acetato)diaquadicopper model system (CCDC reference 1811668). The effect of the resolution [sin(θ)/λ], the Cu scattering factor, the inclusion of anisotropic displacement parameters and the positions of the atoms in the refinement are considered in terms of statistical error analysis, residual and deformation density maps, Atoms In Molecules parameters, d-orbital populations, and others. The choice of the neutral Cu scattering factor in the HC refinement is found to give the most satisfactory results for most of the monitored parameters, despite the formal Cu nature of copper in the studied complex. In order to put the difference between the HC model and the reference DFT (BLYP functional) results on the right scale, several computational chemistry methods (B3LYP, Hartree-Fock, Møller-Plesset perturbation theory and Coupled Clusters Singles and Doubles) were compared with the chosen DFT reference. Differences in the magnitudes of the structure factors and AIM parameters are presented, including considerations of relativistic effects and periodic boundary conditions, i.e. a comparison of a molecular crystal calculation versus an isolated molecule in the crystal.
在本研究中，针对四（μ - 乙酸根）二水合铜模型体系（CCDC参考文献1811668）的密度泛函理论（DFT）参考计算得到的结构因子，研究了多极汉森 - 科彭斯（HC）模型精修的灵活性。从统计误差分析、残余和变形密度图、分子中的原子参数、d轨道布居等方面，考虑了分辨率[sin(θ)/λ]、铜散射因子、各向异性位移参数的纳入以及精修中原子位置的影响。尽管所研究配合物中铜具有形式上的铜性质，但发现在HC精修中选择中性铜散射因子能为大多数监测参数给出最令人满意的结果。为了将HC模型与参考DFT（BLYP泛函）结果之间的差异置于正确的尺度上，将几种计算化学方法（B3LYP、哈特里 - 福克、莫勒 - 普莱斯塞微扰理论和耦合簇单双激发）与所选的DFT参考进行了比较。给出了结构因子和分子中的原子参数大小的差异，包括相对论效应和周期性边界条件的考虑，即分子晶体计算与晶体中孤立分子的比较。
