To better understand the diffusion behaviors of Tc(IV)-L complexes in the water-rock system, the diffusion coefficients (D_w) of VO²⁺ [as a surrogate to ⁹⁹Tc(IV)] and their complexes with ligands (Oxalate, NTA and EDTA) in water were studied by a capillary method. The density functional theory was employed to investigate the complexation between VO²⁺ and ligands. The D_w values of [VO(Ox)₂]²⁻, [VO(NTA)]⁻ and [VO(EDTA)]²⁻ were 18–26% higher than that of VO²⁺ due to the smaller molecular radii of the complexes.

中文翻译：

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钒(IV)-配体配合物扩散和分子结构的毛细管方法和分子动力学研究

为了更好地理解TC（IV）在水岩系统-L络合物，扩散系数（的扩散行为d_瓦特VO的）²⁺ [作为替代，以⁹⁹锝（IV）]以及它们与配体的络合物（草酸盐、NTA 和 EDTA) 在水中通过毛细管方法进行研究。密度泛函理论被用来研究VO ²⁺和配体之间的络合。[VO(Ox) ₂ ] ²⁻、[VO(NTA)] ⁻和[VO(EDTA)] ²⁻的D _w值比VO ²⁺的D _w值高18-26%，这是由于其分子半径较小复合体。