^(79)BrF和^(81)BrF基态X^1∑^+光谱性质同位素效应对结构性质的影响

The influences ofmolecule structure fromthe spectrum isotopic effect between ^(79)BrFand ^(81)BrF in the X^1∑^+

采用原子分子静力学的基本原理分析了BrF基态X^1∑^+的离解极限,采用Herzberg同位素理论分析了BrF基态X^1∑^+光谱数据的同位素效应,并以此为基础,分析了光谱数据的同住素效应对振动能级和分子势能函数(Murrell-Sorbie势即MS势)的影响.结果表明,^(79)BrF和^(81)BrF基态X^1∑^+的光谱数据的同住素效应是一种弱效应,与Herzberg同住素理论符合得很好,低振动能态的能级对理论预计的偏离很小,高阶力常数f_4和高阶展开系数a_3与实验结果有较大偏差,但由于a_3本身比a_1和a_2小很多,结果对势能函数整体影响不大.

The dissociation limit of BrF in the X1 ground state are analysed with Atomic and Molecular Reaction Statics. The spectrum isotopic effect between 79BrFand 81BrF in the X1 are analysed with Herzberg’s isotopic theory. Based on the analysis, the isotopic influence for the vibration energy levels and the molecular potential energy function as Murrell-Sorbie potential （MS potential） are discussed. The results show that the spectrum isotopic effect between 79BrF and 81BrF in the X1 is a kind of weak effect and are agreement with Herzberg’s isotope theory, the deviation of low vibration level between experiment and Herzberg’s isotope theory are small, for higher-order force constant f4 and higher-order spread coefficient a3, theoretical and experimental results have clearer differences, but the effect for the potential energy function is not obvious as the spread coefficient a3 is much smaller than a1 and a2, the overall impact on the potential energy function is not clear.