Unusual Dimer Structures of the Heavier Alkaline Earth Dihalides: A Density Functional Study
Unusual Dimer Structures of the Heavier Alkaline Earth Dihalides: A Density Functional Study
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较重碱土二卤化物的不寻常二聚体结构：密度泛函研究
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
M. Hargittai
中科院分区：
文献类型：
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作者：
J. B. Levy;M. Hargittai
密度泛函理论已应用于研究较重碱土金属的单体和二聚二卤化物。利用了金属上的准相对论赝势和具有未收缩的 d（和 f）极化函数的大基组以及卤素上的相关一致的全电子基组。人们发现 SrF2、BaF2 和 BaCl2 的单体确实是弯曲的，而 CaF2 和 SrCl2 虽然也是弯曲的，但具有极其平坦的势能表面，并且更好地描述为拟线性。对较重的碱土金属二氟化物和二氯化物 Ca2F4、Ca2Cl4、Sr2F4、Sr2Cl4、Ba2F4 和 Ba2Cl4 的二聚体进行了详细研究。计算了二卤化锶和二卤化钡二聚体的六种不同异构体。典型的D2h对称卤桥结构仅对于较轻的二卤化物的二聚体是最稳定的，对于较重的二聚体来说它不是稳定的结构。对于这些分子，三桥 C3v 对称结构是最安全的...
Density functional theory has been applied to investigate the monomeric and dimeric dihalides of the heavier alkaline earth metals. Quasirelativistic pseudopotentials and large basis sets with uncontracted d (and f) polarization functions on the metals and correlation-consistent all-electron basis sets on the halogens were utilized. The monomers of SrF2, BaF2, and BaCl2 were found to be genuinely bent, while CaF2 and SrCl2, although also bent, have extremely flat potential energy surfaces and are better described as quasilinear. The dimers of the heavier alkaline earth difluorides and dichlorides, Ca2F4, Ca2Cl4, Sr2F4, Sr2Cl4, Ba2F4, and Ba2Cl4, were investigated in great detail. Six different isomers were calculated for the strontium and barium dihalide dimers. The typical D2h symmetry halogen-bridged structure is the most stable only for the dimers of the lighter dihalides, and it is not a stable structure for the heavier dimers. For these molecules, a triple-bridged C3v symmetry structure is the most s...