Density functional calculations of (207)Pb NMR shielding in PbX(2) (X=F, Br, Cl and I) anionic fragments suggest that in solid PbX(2), the observed variation of chemical shift with halide is dominated by the paramagnetic contribution to the chemical shielding, with a lesser effect by the spin-orbit contribution. The calculations include relativistic effects at the level of the zero-order regular approximation (ZORA). The present observation contrasts with previous calculations for the molecular system, PbX(4), in which the spin-orbit contribution has been shown to be the major factor in the variation of the NMR chemical shift.

中文翻译：

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相对论的ZORA-DFT形式论对固体离子铅（II）卤化物的（207）Pb NMR参数的预测：与含铅分子系统的比较。

在PbX（2）（X = F，Br，Cl和I）阴离子片段中进行（207）Pb NMR屏蔽的密度泛函计算表明，在固体PbX（2）中，观察到的卤化物化学位移的变化主要由顺磁性决定对化学屏蔽的贡献，自旋轨道贡献的影响较小。计算包括零级正则逼近（ZORA）级别的相对论效应。本观察结果与先前对分子系统PbX（4）的计算形成了对比，在分子系统中，自旋轨道的贡献已被证明是NMR化学位移变化的主要因素。