NO自由基基态的分子结构与势能函数

Structure and potential energy function of NO free radical ground state

利用原子分子反应静力学的有关原理,推导出了NO分子的合理离解极限;使用HF、CID、B3P86和B3LYP等理论方法,在D95(d)、6-311G(3df,3pd)和D95(3df,3pd)基组下,对NO分子基态的平衡结构和谐振频率进行了优化计算,且将计算结果(平衡核间距0.11518 nm、谐振频率1981.42 cm-1、离解能6.648 eV)与实验结果(平衡核间距0.11508 nm、谐振频率1904.7 cm-1、离解能6.614 eV)进行了比较,得出了B3LYP方法为最优方法、基组D95(3df,3pd)为最优基组的结论.利用B3LYP/D95(3df,3pd)对NO分子的基态进行了单点能量扫描,并将扫描结果用正规方程组拟合成了Murrell-Sorbie势能函数.由拟合得到的势能函数,计算与X2Π态相应的光谱常数(Be、αe、ωe和ωeχe),其结果与实验符合得较好.

the possible electronic states and their reasonable dissociation limits for NO are determined based on the atomic and molecular reaction statics.The equilibrium separation of 0.11518nm,the harmonic frequency of 1981.42cm^-1 and the dissociation energy of 6.648eV about this state have been accurately calculated of（X^2Π） state,Using the method as HF,CID,B3P86 and B3LYP and the basis sets of D95（d）,6-311G（3df,3pd） and D95（3df,3pd）,comparing among above-mentioned three basis sets,the conclusion is gained that the basis set D95 （3df,3pd） the most suitable for the energy calculation of NO molecule,the whole potential curves for the ground state and scanned using B3LYP/D95 （3df,3pd） ,then have a least square fitted to Murrell-Sorbie function, and last spectroscopy Constants （Be,αe,ωe,and ωeχe） are calculated, which are in good agreement with the experimental data.