MRCI计算研究B2+分子的结构和解析势能函数

采用从头计算的多参考组态CI方法(MRCI) 和B原子Dunnings相关调和基函数含扩散基的大基组aug-cc-pVQZ对B+2分子的基态和低激发态的势能曲线进行计算 .利用Huxley函数、Murrell-Sorbie函数和最小二乘法拟合出了解析势能函数,并以此为基础计算出光谱常数.通过比较发现:Huxley 函数比MS函数的拟合方差更小,能更好地再现分子中原子间相互作用.采用两种函数所得解析势能函数与从头计算势能曲线间的误差RMS 均远小于化学精度4.184 kJ/mol的要求,表明所得解析势能函数很好地再现了这些态中原子间的相互作用情况,可用于更广泛的研究.

MRCI study of analytical potential energy function and spectroscopic parameters of B+2 molecule

The potential energy curve for the ground state and low-lying excited state of B~ _2 molecule have been computed using MRCI method and Dunning's correlation consistent basis aug-cc-pVQZ. By employing Huxley and Murrell-Sorbie function as well as least square fitting method, the analytical potential energy functions of the states are induced. Based on this, we calculate the spectroscopic parameters. Present study shows that Huxley function is better than Murrell-Sorbie function and can re-display the interaction between atoms well. The RMS errors between the fitted results and ab initio values are too little in comparison with the chemical accuracy 4.184 kJ/mol. It shows that the present analytical potential energy functions are accurate, and can be used to more investigations.