This study compares results of four relativistic pseudopotential basis sets, which differ mainly by their size: double‐zeta introduced by Hay and Wadt from Los Alamos National Laboratory (LANL2DZ), triple‐zeta based on Stuttgart energy‐consistent scalar‐relativistic pseudopotential (SDD3), its extension with 2fg polarization functions, and combination of Stuttgart pseudopotentials with quintuple‐zeta cc‐pV5Z base (SDD5). Hydrides of transition metals from Cr to Zn group are chosen as reference molecules. The coupled cluster method (CCSD(T)) is used for evaluation of selected molecular characteristics. Interatomic distances, dissociation energies, vibration modes, and anharmonicity constants are determined and compared with available experimental data. As expected, the accuracy of basis depends mainly on its size. However, only moderate modification of SDD3 basis set significantly improves its accuracy, which becomes comparable to the largest basis set. Nevertheless, the time consumption is significantly lower.

中文翻译：

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过渡金属氢化物的量子力学研究：确定的分子性质与实验数据的比较

本研究比较了四种相对论赝势基组的结果，它们的主要区别在于其大小：洛斯阿拉莫斯国家实验室的 Hay 和 Wadt 引入的双 zeta 基组（LANL2DZ）、基于斯图加特能量一致标量相对论赝势基组的三 zeta 基组（SDD3 ），其具有 2fg 极化函数的扩展，以及斯图加特赝势与五重 zeta cc-pV5Z 基（SDD5）的组合。选择从 Cr 到 Zn 族的过渡金属氢化物作为参考分子。耦合簇方法（CCSD(T)）用于评估选定的分子特征。确定原子间距离、离解能、振动模式和非谐常数，并与可用的实验数据进行比较。正如预期的那样，基础的准确性主要取决于其大小。然而，仅对 SDD3 基组进行适度修改即可显着提高其准确性，其精度可与最大基组相媲美。尽管如此，时间消耗却显着降低。