用ab initio方法研究NaH(NaD)分子的结构及其基态(X^1∑^+)的势能函数

Structures and potential energy function of the ground state of NaH(NaD) molecules

运用群论和原子分子静力学方法,推导了NaH(NaD)分子基态的合理离解极限。采用两种方法和三种基组优化计算了NaH(NaD)分子基态的平衡结构和离解能。选用电子相关单双取代耦合簇CCSD(T)方法结合6-311++G(3df,3pd)基组对NaH(NaD)分子基态进行了单点能扫描计算。用最小二乘法拟合Murrell-Sorbie函数,计算得到了NaH(NaD)分子基态的势能函数和对应的光谱常数。结果表明,采用Murrell-Sorbie函数计算所得的光谱常数与实验结果符合的很好,能精确地描述NaH(NaD)分子基态的势能函数。

Based upon the group theory and atomic and molecular statics,the ground states and the dissociation limits of NaH（NaD） radical are determined.The equilibrium structures and dissociation energies of the ground states of NaH（NaD） are calculated by using several methods of different basis sets.The potential curve of the ground state is scanned by using the（QCISD（T））6-311＋＋G（3df,3pd） basis set. The potential energy function and relevant spectroscopic constants of this state are obtained by fitting to the Murrell-Sorbie function.The result shows that the spectroscopic constants derived from the Murrell-Sorbie function are in very good agreement with the experimental data,which indicated that the MurrellSorbie function can correctly present the potential energy function of the ground state of NaH（NaD） radical.