气相环境Ala分子和离子的低激发态性质

用密度泛函理论中的B3LYP方法, 在6-311++G(-d,p-)基组水平上, 优化得到气相环境丙氨酸分子和带电离子的基态稳定构型, 并用含时密度泛函理论（TD-DFT)方法研究气相环境丙氨酸分子和负离子的低激发态特性. 结果表明, 随着体系分子获得电子数的增加, 键长呈逐渐减小趋势, 第一激发态的激发能Δ E明显减小, 荧光波长急剧增加, S6电子跃迁轨道数增加.

Characteristics of Ala Molecule and Ions in Low Excited States

Using the method of density functional B3LYP, we optimized the ground state stable geometries of the gas phase alanine (Ala) molecules and charged ions at the level of 6-311++G(-d,p-) basis set. The method of time dependent density functional theory (TD-DFT) was used to study the low excited state properties of the gas phase Ala molecules and ions. The results show that the bond length gradually decreases, the excitation energy of the first excited state decreases, the fluorescence wavelength increase sharply, and the number of electronic transition orbit of S6 increases with the increases of the number of electrons obtained by molecules.