Quantum crystallographic refinement of heavy-element-containing compounds is a challenge, because many physical effects have to be accounted for adequately. Here, the impact and magnitude of relativistic effects are compared with those of electron correlation, polarization through the environment, choice of basis set and treatment of thermal motion effects on the structure factors of diphenylmercury(II) [Hg(Ph)2] and dicyanomercury(II) [Hg(CN)2]. Furthermore, the individual atomic contributions to the structure factors are explored in detail (using Mulliken population analysis and the exponential decay of atomic displacement parameters) to compare the contributions of lighter atoms, especially hydrogen atoms, against mercury. Subsequently, relativistic Hirshfeld atom refinement (HAR) is validated against theoretical structure factors of Hg(Ph)2and Hg(CN)2, starting from perturbed geometries, to test if the relativistic variant of HAR leads to multiple solutions. Generally, relativistic HAR is successful, leading to a perfect match with the reference geometries, but some limitations are pointed out.

中文翻译：

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二苯基和二氰基汞的相对论量子晶体学。理论结构因素和赫什菲尔德原子细化

含重元素化合物的量子晶体学精炼是一项挑战，因为必须充分考虑许多物理效应。在这里，相对论效应的影响和大小与电子关联、环境极化、基组的选择以及热运动效应的处理对二苯汞(II) [Hg(Ph) 的结构因素的影响和大小进行了比较。2] 和二氰汞(II) [Hg(CN)2]。此外，还详细探讨了单个原子对结构因素的贡献（使用马利肯布居分析和原子位移参数的指数衰减），以比较较轻原子（尤其是氢原子）与汞的贡献。随后，根据 Hg(Ph) 的理论结构因素验证了相对论赫什菲尔德原子细化 (HAR)2和汞（CN）2，从扰动几何结构开始，测试 HAR 的相对论变体是否会产生多个解。一般来说，相对论 HAR 是成功的，可以与参考几何完美匹配，但也指出了一些局限性。