The polarisability of Hg and the ground-state interaction potential of Hg2

Summary The Hg atom electric polarisability at MP3, MP4, QCISD or QCISD(T) level using a 20 valence-electron pseudopotential and a (9s8p7d2f)/[7s6p4d2f] basis set converges and agrees with experiment. The calculated Hg₂ X ¹ V (R) at the same level is roughly half of experiment atR _e but twice as large as the experimentalC ₆ at largeR.Dedicated to Inga Fischer-Hjalmars whose wit and charm made Quantum Chemistry a better place On leave of absence from: Department of Chemistry, Peking University, Beijing 100871, People's Republic of China     

溶液中类锗烯H2GeClMgCl的结构与异构化反应

用密度泛函理论(DFT)和QCISD(quadratic configuration interaction with single and double excitations)方法研究了类锗烯H2GeClMgCl在气相和五种溶剂中的构型与异构化反应. 结果表明, 类锗烯H2GeClMgCl有三种平衡构型. 其中p-配合物型构型能量最低, 是其存在的主要构型. 讨论了溶剂效应对结构、能量与异构化反应的影响. 计算模拟了最稳定构型的红外光谱.     

Theoretical Studies on the Reaction Mechanism of AsCl3 with H2 in the Vapor Phase Epitaxy of GaAs

The reaction mechanism of AsCl3 with H2 has been studied by using the method of BHandHLYP in Density Functional Theory (DFT) at the 6-311G** basis set. The transition state of each reaction is verified via the analysis of vibration mode and Intrinsic Reaction Coordinate (IRC). Meanwhile,single-point energy has been calculated at the QCISD(T)/6-311G** level,and the zero-point energy correction has been made to the total energy and reaction energy barrier. It shows that AsCl3 reacts with H2 to first result in AsHCl2 which may incline to self-decompose and finally afford the product As2,or continue to react with H2 to provide the product AsH3. The computing result demonstrates that the former is the main reaction channel.     

CH2Cl和O2的反应动力学

利用时间分辨傅立叶变换红外发射光谱技术研究了CH2Cl+O2的气相基元反应．在实验中首次观测到了振动激发产物CO (v·4)和CO2(o3,v·7)．激发态的CO/CO2 (o3)比率是72.2§7．在QCISD//UB3LYP/6-311++G (d, p)水平上对该化学反应的中间物和产物进行了量子化学计算．其研究结果表明: CH2Cl 自由基首先和O2结合, 生成中间物CH2ClOO， 紧接着发生脱氯反应生成环氧中间物CH2OO，然后再经过一系列的异构化和分解反应，生成最终的产物CO和CO2，和实验观     

F2 dimer: Improved intermolecular potential energy surface using ab initio calculations

A computational study on the intermolecular potential energy of 44 different orientations of F₂ dimers is presented. Basis set superposition error (BSSE) corrected potential energy surface is calculated using the supermolecular approach at CCSD(T) and QCISD(T) levels of theory. The interaction energies obtained using the aug‐cc‐pVDZ and aug‐cc‐pVTZ basis sets are extrapolated to the complete basis set limit using the latest extrapolation scheme. The basis set effect is checked and it is found that the extrapolated intermolecular energies provide the best compromise between the accuracy and computational cost. Among 1320 energy points of F₂–F₂ system covering more relative orientations, the most stable structure of the dimers was obtained with a well depth of ?146.62 cm^?1 that related to cross configuration, and the most unstable structure is related to linear orientation with a well depth of ?52.63 cm^?1. The calculated second virial coefficients are in good agreement with experimental data. The latest extrapolation scheme of the complete basis set limit at the CCSD(T) level of theory is used to determine the intermolecular potential energy surface of the F₂ dimer. Comparing the results obtained by the latest scheme with those by older schemes show that the new approach provides the best compromise between accuracy and computational cost.     

XY(H,Li, Na)分子基态的结构与势能函数

运用群论及原子分子反应静力学方法，推导了XY(H，Li，Na)分子基态的电子态及相应的离解极限.并采用密度泛函方法(B3LYP)和二次组态相互作用方法(QCISD)优化计算了XY(H，Li，Na)分子基态的平衡结构、振动频率和离解能.使用QCISD/6-311++G(3df,3pd)方法，对XY(H，Li，Na)分子基态进行了单点能扫描计算，采用最小二乘法拟合Murrell-Sorbie函数得到了相应的势能函数和与该基态相对应的光谱常数(B_e,α_e,ω_e和ω_eχ_e)，计算结果与实验数据符合得相当好. 关键词： 组态相关方法 基态 势能函数     

HONO与HCl反应的量子化学研究

用量子化学密度泛函理论(DFT)和四次组态相互作用(QCISD(T)),对HONO与HCl的反应进行了研究.在B3LYP/6-311G**计算水平上,优化了反应势能面上各驻点的几何结构.在QCISD(T)/6-311G**水平上计算了单点能量.确定了反应机理,HONO与HCl反应主要生成产物为ClNO H2O.     

溶液中类锗烯H2GeClMgCl的结构与异构化反应

用密度泛函理论(DFF)和 QCISD (quadratic configuration interaction with single and double excitations)方法研究了类锗烯 H2CeCMgCl在气相和五种溶剂中的构型与异构化反应.结果表明,类锗烯 H2GeClMgCl有三种平衡构型.其中p-配合物型构型能量最低,是其存在的主要构型.讨论了溶剂效应对结构、能量与异构化反应的影响.计算模拟了最稳定构型的红外光谱.