密度泛函方法对NF分子基态势能函数的研究

Study on the Potential Energy Function for the Ground State of NF Molecule by Density Functional Theory

利用原子分子反应静力学的有关原理,推导出了NF分子基态的合理离解极限;采用密度泛函理论的B3LYP方法,在相关一致基cc-PVnZ(n=2,3,4,5)及aug-cc-PVnZ(n=2,3,4,5)基组下,对NF分子基态的平衡几何、离解能和谐振频率进行了优化计算,利用B3LYP/aug-cc-PV5Z对NF分子的基态进行了单点能量扫描,采用最小二乘法拟合Murrell-Sorb ie势能函数,得到势能函数和与该态相应的光谱常数(eβ、αe、ωe和ωeeχ),其结果与实验符合得较好.

The possible electronic states and their reasonable dissociation limits for NF at the ground state were determined based on the atomic and molecular reaction statics. The dissociation energy, equilibrium geometry and harmonic frequency of the ground state X^∑^- were calculated by using density functional theory B3LYP method at the basis sets of ce-PVnZ （n = 2,3,4,5 ） and aug-cc-PVnZ （n = 2,3,4,5 ）. The whole potential curve as a function of the NF distance was scanned using B3LYP/aug-ee-PVSZ. The potential energy function and relevant spectroscopy constants （βe、αe、ωe and ωeχe ） of this state were obtained by least square fitting to the Murrell-Sorbie function. All results are in good agreement with the experimental data.