摘要
用密度泛函理论的B3LYP方法,对钯和钇原子采用SDD收缩价基函数,氢原子采用6-311++G全电子基函数,对PdH2和YH2体系的结构进行优化计算,得到PdH2分子最稳态为C2v构型,电子组态为1A1,平衡核间距RPdH=0.1692nm,键角∠HPdH=29.4°,离解能De=5.5212eV,基态简正振动频率:ν1(b2)=1470.1cm-1、ν2(a1)=1007.9cm-1、ν3(a1)=2907.0cm-1.YH2分子最稳态也为C2v构型,电子组态2A1,RYH=0.1962nm,∠HYH=114.3°,De=5.6691eV,基态简正振动频率:ν1(b2)=1457.9cm-1、ν2(a1)=476.0cm-1、ν3(a1)=1506.3cm-1.由微观过程的可逆性原理分析了分子的可能离解极限.并用多体项展式理论方法分别导出基态PdH2和YH2分子的势能函数,其等值势能面图准确地再现了PdH2和YH2分子的结构特征和离解能,由此讨论了Pd+H2和Y+H2分子反应的势能面静态特征.
Density functional (B3LYP) method has been used to optimize the possible structures of PdH2 and YH2 molecules by contracted valence basis set (SDD) for Pd and Y atoms, the 6-311 + + G** basis set for H atom. The results show that the ground state of PdH2 molecule is C-2. symmetry and X-1 A(1) state. The parameters of structure and the harmonic frequencies are R-PdH = 0. 1692 nm, <HPdH = 29. 4degrees, D-e = 5. 5212 eV and nu(1) = 1470. 1 cm(-1), nu(2) = 1007. 9 cm(-1), nu(3) = 2907. 0 cm(-1) respectively. The results also show that the ground state of YH2 molecule is C-2nu symmetry and X-2 A(1) state. The parameters of structure and the harmonic frequencies are R-YH = 0. 1962 nm, <HYH = 114. 3degrees, D-e = 5. 6691 eV and nu(1) = 1457. 9 cm(-1), nu(2)= 475. 9 cm(-1), nu(3) = 1506. 3 cm(-1) respectively. The potential energy functions of PdH2 and YH2 have been derived from the normal equation fitting and the many-body expansion theory which is successfully used for describing the equilibrium geometry of PdH2 and YH2. Molecular reaction kinetics of Pd + H-2 and Y + H-2 based on this potential energy function is discussed briefly.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2004年第11期1380-1384,共5页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(10176021)资助项目~~~
关键词
PdH2
YH2
分子结构
势能函数
PdH2
YH2
molecular structure
potential energy function
