【作者】 王珺；

【导师】 刘煜炎；

【作者基本信息】 华东师范大学 ， 光学， 2004， 硕士

【摘要】 水分子离子在天体物理、化学物理、生物物理以及生命起源和寻找外星生物的研究中占有重要地位，由于它的X²B₁态和A²A₁态具有Renner-Teller效应，使得A²A₁-X²B₁的跃迁光谱线异常复杂，对谱线的指认工作比较困难，非常需要理论数据提供参考。目前，H₂O⁺激发态的理论数据还不多，激发态的势能面计算是H₂O⁺理论计算的重要一环。 本论文针对H₂O⁺的激发态，运用GAUSSIAN98程序对其势能面进行了计算，从活性空间的选取、初始预测轨道的设置、基组对结果的影响三个方面进行了讨论，最后采用活性空间CAS（3，4）和基组6-31+G（d，p）得到了H₂O⁺激发态的势能曲面，对其进行拟合，得到H₂O⁺激发态势能面的解析表达式。所得到的势能曲面与MRD-CI方法得到的结果基本一致。更多还原

【Abstract】 The H2O+ cation has been of great importance for elementary research processes in astrophysics, physical chemistry, biophysics, the origin of lives and the search forlives in outer space. The X2B1 and A2A1 electronic states are subject to theRenner-Teller effect, resulting in a complicated A2A1 -X2B1 emission spectrum andassignment. It is very necessary to have theoretical data to reference. Nowadays, it is an important step to study the potential energy surface of H2O+ considering few data of the excited state of it.In the present paper, the excited potential surface of H2O+ is calculated by using CASSCF method with GAUSSIAN98 program. We discussed the selection of complete active space(CAS), the orbitals within the initial guess and results with different basis sets during CASSCF calculation. At the same time, we calculated the excited potential surface of H2O+ at the CAS(3,4)/6-31+G(d, p) level, then fitted to analytical expression. The potential surface obtained is agreed very well with the result from MRD-CI method .更多还原