基于NTO类型图解苏氨酸分子体系的价层激发

在B3LYP/6-31G(d)基组水平上优化隐式溶剂甲醇下右旋体苏氨酸（R-Thr)分子的几何构型， 根据该结构， 在Mo6-2X/6-311G(d)、TZVP和def2-TZVP基组水平上， 用含时密度泛函理论（TDDFT）方法进行电子激发计算，并通过指认自然跃迁轨道（NTO）类型方法研究R-Thr-CH₃OH分子体系价层电子激发类型. 结果表明: TZVP基组与def2-TZVP基组激发类型判断结果基本一致，6-311G(d)基组与其他两种基组水平对比， 激发类型判断结果差异较大；NTO类型分析与理论数据Δr指数分析配合使用，对R-Thr-CH₃OH分子体系电子激发类型和激发模式指认具有实际意义.

Valence Layer Excitation of Threonine Molecular System Based on NTO Type Diagrams

The geometry of R-threonine (R-Thr) molecules in the implicit solvent methanol was optimized at the B3LYP/6-31G(d) basis set level, based on this structue, the time-dependent density functional theory (TDDFT) method was used to calculate the electronic excitation at the Mo6-2X/6-311G(d),TZVP,def2-TZVP basis set level, and the valence layer electronic excitation type of R-Thr-CH₃OH molecular system was studied by the method of identifying the type of natural transition orbit (NTO). The results show that the judgement results of TZVP and def2-TZVP basis sets are basically consistent, 6-311G(d) basis set is compared with the other two basis sets, there is a big difference in the judgment results of excitation type. The combination of NTO type analysis and Δr indes analysis of theoretical data has practical significance for the identification of the electronic excitation type and excitation mode of R-Thr-CH₃OH molecular system.