PdCO分子结构与势能函数

用密度泛函理论的B3LYP方法，对钯原子采用LANL2DZ收缩价基函数，碳原子和氧原子采用AUG-cc-pVTZ基组，对PdC，PdO和PdCO体系的结构进行优化，计算表明：PdC分子基态为¹Σ⁺态，键长为R_e=0.17285nm，离解能为4.919eV.PdO分子基态的平衡核间距为0.18546nm，其电子态为³Π，离解能为2.455eV，并拟合得到Murrell-Sorbie势能函数；PdCO分子有两 关键词： PdCO 分子结构 势能函数

The structure and potential energy function of PdCO molecule

Density functional method(B3LPY) has been used to optimize the possible structures of PdC，PdO and PdCO molecules with contracted valence basis set (LANL2DZ) for Pd atom and the AUG-cc-pVTZ basis set for C and O atoms respectively.It was found that the ground state of PdC molecule is ¹Σ，whose equilibrium nuclear distance and dissociation energy are R_PdC=0.17285nm and 4.919eV, respectively.The ground state of PdO molecule is ³Π with equilibrium geometry R_PdO=0.18546nm and dissociation energy D_e=2.455eV. The ground state of the linear Pd—C≡O (C_∞v) is ¹Σ⁺ and the configuration and dissociation energy are R_PdC=0.18721nm，R_CO=0.11427nm and 12.563eV, respectively. At the same time， another metastable structure Pd—O≡C(C_∞v) was found. Its equilibrium geometry and dissociation energy are R_CO=0.11336nm， R_PdO=0.23001nm and 10.937eV, respectively.The possible dissociation limit of PdCO molecule is determined.The analytical potential energy function for PdCO molecule has been obtained from the many-body expansion theory.The contour of the potential energy surface sheds light on the accurate structure and dissociative energy for PdCO molecule.Furthermore, the molecular static reaction pathway based on this potential energy function is investigated.