检查了几种在 B3LYP/6-31 + G(d,p) 几何结构下具有 6-311 + G(2df,2p) 基组的 DFT 方法，以计算某些乙内酰脲衍生物的准确绝热电子亲和力 (AEA)。这些方法的准确性相对于使用 G4、G3B3 和 CBS-QB3 方法获得的标准参考 AEA 进行了统计检验。结果表明，B3PW91、TPSSTPSS 和 B3LYP 方法分别获得了最小 RMSE 值。B3PW91 方法与 B3LYP/6-31 + G(d,p) 几何结构下的 6-311 + G(2df,2p) 基组相结合，用于计算某些乙内酰脲药物的 AEA，包括苯妥英、呋喃妥因、呋喃妥因、尿囊素、异普定、乙妥英和美芬妥英，以及一些苯妥英和呋喃妥因衍生物。而且，所有研究化合物的垂直电子亲和力 (VEA) 均使用 B3LYP/6–31 + G(d,p) 水平计算。研究并讨论了 AEA 值的替代效应。结果表明，给电子基团降低了 AEA 和 VEA 值，而吸电子基团则相反。此外，NBO 分析用于计算中性和阴离子物种的自然自旋密度和原子电荷。所得结果表明，一般来说，最大自旋密度位于乙内酰脲环的羰基碳原子上。还研究和讨论了阴离子与中性分子相比几何结构（键长和键角）的变化。AEA 和 VEA 与能隙之间的相关性与相关系数 (R2）显示接近统一。此外，还计算了一些乙内酰脲衍生物和药物在水溶液中的AEA和VEA，并将其结果与气相结果进行了比较。

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Several DFT approaches with 6–311 + G(2df,2p) basis set at the B3LYP/6–31 + G(d,p) geometries were examined to calculate accurate adiabatic electron affinity (AEA) for some hydantoin derivatives. The accuracy of these approaches was statistically examined with respect to the standard reference AEA, which obtained by using G4, G3B3 and CBS-QB3 methods. The results reveal that the least RMSE values were obtained for B3PW91, TPSSTPSS and B3LYP approaches, respectively. The B3PW91 approach in conjunction with the 6–311 + G(2df,2p) basis set at the B3LYP/6–31 + G(d,p) geometries were used to calculate the AEA for some hydantoin drugs, including Phenytoin, Nitrofurantoin, Allantoin, Iprodine, Ethotoin and Mephenytoin, as well as some of phenytoin and nitrofurantoin derivatives. Moreover, the vertical electron affinity (VEA) of all investigated compounds were calculated using the B3LYP/6–31 + G(d,p) level. The substitution effects on the AEA values were studied and discussed. The results reveal that the electron donating groups decrease the AEA and VEA value, whereas, the reverse is true in the case of the electron withdrawing groups. Furthermore, NBO analysis was used to calculate the natural spin density and atomic charges of the neutral and anion species. The results obtained show, in general, that the maximum spin density is located on the carbonyl carbon atom of the hydantoin ring. The changes in the geometrical structures (bond lengths and bond angles) of anions compared to the neutral molecules were also studied and discussed. Correlations between the AEA and VEA with the energy gap with the correlation coefficients (R2) close to unity were shown. Furthermore, the AEA and VEA for some hydantoin derivatives and drugs were also calculated in aqueous solution, and their results are compared with the gas phase results.