U+与CO2气相反应的密度泛函理论研究

运用密度泛函理论(DFT)中的B3LYP方法,U原子用含相对论有效原子实势(ECP)校正的基组(SDD),C、O原子采用6-311+G(d)基组,对气相中U+和CO2的反应进行了理论研究.通过研究二重和四重自旋态的反应势能面(PESs),优化得到了两条反应路径的反应物、中间体、过渡态和产物的结构.用"两态反应"(TSR)分析反应机理,结果表明体系的优先选择路径为高自旋态进入和低自旋态离开反应,发生在四重态和二重态的自旋多重度的改变使得整个反应系统能以一个低能反应途径进行.

Density Functional Theory Study of the Gas-Phase Reaction of U+ with CO2

The gas-phase reaction of U⁺ with CO₂ was investigated with B3LYP density functional theory (DFT) in conjunction with the relativistic effective core potential (ECP) of the SDD basis sets for Uand the 6-311 + G(d) basis set for C and O. The potential energy surfaces (PESs) of the reaction system were explored in detail for both doublet and quartet spin states. The geometries of reactants, intermediates, transition states, and products in the two reaction pathways were fully optimized. The reaction mechanism was analyzed using"two-state reactivity (TSR)."The calculations demonstrate that the reaction preferentially involves the high-spin state entrance channel and the low-spin state exit channel. The spin multiplicity transition from the quartet state to the doublet state enables the reaction system to find a lower energy pathway.