基态的HCN和HNC分子的势能面

运用密度泛函理论(DFT)的B3LYP方法在6-311++G**水平上，对基态HCN和HNC分子的结构进行了优化计算,得到HCN分子的稳定结构为C∞v构型,电子态为X1∑+u,平衡核间距RH-C=0.1066 nm、RC-N=0.1149 nm,离解能De=18.88 eV; HNC分子的稳定结构为C∞v构型,电子态为X1∑+u,平衡核间距RH-N=0.09996?nm、RN-C=0.1169?nm,离解能De=18.256?eV,用多体项展式理论推导了基态HCN和HNC分子的解析势能函数,其等值势能图准确再现了基态HCN和HNC分子的结构特征及其势阱深度与位置.

The potential energy surfaces of HCN and HNC molecules in the ground state

The density function (B3LYP) method has been used to optimize the possible ground-state structures of HCN and HNC molecules. The results show that for HCN molecule the ground state has C∞v symmetry and is in the X1∑+u state, its parameters of structure are RH-C=0.1066 nm, RC-N=0.1149 nm, De=18.88 eV, respectively, and for HNC molecule has C∞v symmetry and is in the X1∑+u state, its parameters of structure are RH-N=0.09996 nm, RN-C=0.1169 nm, De=18.256 eV, respectively. The potential energy functions of HCN and HNC, derived from the many-body expansion theory, describe correctly the configurations and the dissociation energies of the two ground-state molecules.