【摘要】 运用群论和原子分子静力学方法,推导了SiH(SiD)自由基分子基态的合理离解极限.采用多种方法和基组组合优化计算了SiH(SiD)自由基分子基态的平衡结构,振动频率和离解能.使用二次组态相互作用方法QCISD(T)结合6-311++g(3df,3pd)基组对SiH(SiD)自由基分子基态进行了单点能扫描计算.对标准的Murrell-Sorbie函数进行修正,用最小二乘法分别拟合Murrell-Sorbie函数和修正的Murrell-Sorbie函数得到了SiH(SiD)自由基分子基态的势能函数和对应的光谱常数.结果表明,修正的Murrell-Sorbie势能函数计算所得光谱常数与实验结果符合很好.表明修正的Murrell-Sorbie函数能更为精确地描述SiH(SiD)自由基分子基态的势能函数.更多还原

【Abstract】 The electronic states of the ground state and the dissociation limit of SiH(SiD)radical are correctly determined based on group theory and atomic and molecular statics.The equilibrium geometries,harmonic frequencies and dissociation energies of the ground state of SiH(SiD)are calculated using several methods with different basis sets.The potential curves of the ground state is scanned using the Quadratic CI method including Single and Double substitutions(QCISD(T)) with 6-311++G(3df,3pd) basis set.The Murrell-Sorbie function is modified.The potential energy functions and relevant spectroscopic constants(ω_e,ω_eχ_e,B_e and α_e) of this state are obtained by least square fitting to the Murrell-Sorbie function and the modified MurrellSorbie function,respectively.The results showed that the spectroscopic constants derived from the modified Murrell-Sorbie function are in very good agreement with the experimental data,which indicated that the modified Murrell-Sorbie function can correctly present the potential energy function of the ground state of SiH(SiD)radical.更多还原