本文利用CCSD方法,分别选用6—311++g(3df,3pd)、6-311++g(2df,2pd)和6—311++g(df,pd)基组对BF分子和BF^+、BF^-离子基态进行了几何优化和频率计算,并进行了单点能扫描计算.用最小二乘法拟合得到了BF^x(X=-1,0,+1)分子离子基态的Murrell—Sorbie势能函数.与实验及理论结果比较表明,本文对BF分子和BF^+离子基态光谱常数(Be,αe,ωe,ωexe)的计算结果达到了很高的精度.文章还首次给出BF一离子基态的光谱常数(Be,αe,ωe,ωexe)和力常数(f2,f3,f4),这将为BF一离子基态的后期研究提供重要参考.研究表明:BF^x(X=-1,0,+1)分子离子基态的势能曲线均具有对应于稳定平衡结构的极小点,说明BF^x(X=-1,0,+1)分子离子基态是稳定存在的.
Based on the Gaussian03 calculation software, CCSD method has been used to optimize the possible ground-state structures of BF molecule, BF+ and BF- molecule ion with the 6-311 + + g (3d f, 3pd), 6-311++g(2df,2pd), and 6-311+ +g(df,pd) basis sets respectively. Frequency and singlepoint energy scan for BFx (X =- 1,0, + 1) have been calculated. Spectral parameters (Be,αe,ωe,ωexe) and force constant ( f2,f3,f4 ) of the BF molecule and BF+ ion ground state are obtained by least square fitting to the Murrell-Sorbie function. All calculation results are in good agreement with experimental data. In this work, spectral parameters (Be,αe,ωe,ωexe) and force constants (f2,f3 ,f4 ) of BF- moleeular ion for ground state are shown for the first time. This calculation may provide a good testing ground for investigation of BF- later. There are minimum points corresponding to stable equilibrium of molecular in potential energy curve ofBFx(X=-1,0,+1). It shows that BF^x(X=-1,0,+1) molecular ion can be stable.