MRCI方法研究BN分子结构和解析势能函数

MRCI Study on Analytical Potential Energy Functions and Spectroscopic Properties of BN Molecule

运用多参考组态相互作用(MRCI)的方法和Dunning相关调和基函数含扩散基的大基组aug-cc-pV5Z,获得了BN分子基态(X3П)和三个激发态(1Σ+,1П,3Σ-)的势能曲线(PECs).利用Murrel-Sorbie(MS)函数和最小二乘法拟合得到它们的解析势能函数(APEFs),拟合误差很小表明所得解析势能函数能够很好地再现BN分子中原子间的相互作用情况,为进一步研究这一体系的动力学性质和构造多体势能函数提供参考.在所得解析势能函数的基础上,通过解核运动的薛定谔方程得到各电子态的光谱常数.

The potential energy curves （PECs） for the ground state （X^3∏） and three excited states （^1∑^＋,^1∏,^3∑^- ） of BN molecule have been computed using the method of muhireference configuration interaction （MRCI） and Dunning＇ s correlation consistent basis sets aug-cc-pVSZ. By employing the Murrell-Sorbie function （MS） as well as least-square fitting method, the analytical potential energy functions （APEFs） of these states are induced. The errors between the fitted results and ab initio values are too little in comparison with the chemical accuracy,which can display the interaction between atoms well. Based on the APEFs, the spectroscopic parameters are calculated by solving Schrodinger equation of nuclear motion. It shows that the present APEFs are accurate, and can be used to construct more complicated function or do some dynamics investigations.