聚合物{[CuII(Hpb) (mal)]H2O}n :单体的量子化学计算和磁性研究

{[Cu^Ⅱ（Hpb）（mal）]H=O}n （Hpb=2-2＇-pyridylbenzimidazole, mal=maleic acid） is a helical chain-like polymer complex. In order to investigate the electronic structure of the complex, the monomer Cu^Ⅱ（Hpb）（mal） was obturated with different functional groups respectively. For these selective segments, the geometry optimizations were conducted by using hybrid DFT （B3LYP）methods to find that the structure obturated with H2O was better consistent with the experiment, and then this model would be used to latter calculations, such as the frontier molecular orbital and the NBO charge population analysis. In addition the magnetic behaviors of this complex were analyzed by experiments and the weak antiferromagnetic couple between copper（Ⅱ） ions was observed. The exchange coupling constant was calculated by DFT based on the spin broken symmetry formalism. The calculated coupling constants were in good agreement with the experimental data.     

若干SO2电子态的势能面

用MRPT2//CASSCF方法和cc-pVTZ基组构建了SO₂分子基态1¹A₁和低激发态2¹A₁, 1¹A₂, 1¹B₁, 1¹B₂, 1³A₁, 1³A₂, 1³B₁, 1³B₂共9个电子态的势能面一维切面. 预测了各态的稳定构型, 激发态的绝热激发能, 与实验数据以及前人的计算有很好的一致性. 对势能面的相交和避免相交情况做了细致的讨论.     

可调节的收缩CI方法

提出了一个新的收缩CI计算方案———可调节收缩CI方案 ,并完成了相应的程序 .通过实例计算考察了该方案的效率 .一系列计算表明 ,新方案的应用比较灵活 ,相关能损失比较小 .     

基于组态的多参考态二级微扰理论

考察了各种基于组态的多参考态二阶微扰理论方法, 提出了一个新的避免出现 Intruder 态的方法, 并完成了各种方案的程序化. 通过实例计算, 考察了这些方案的可行性及其效率,并通过BH分子的势能曲线的计算说明了多参考态方法的重要性.     

An adjustable contracted CI method

A new contracted CI scheme——adjustable contracted CI scheme——is presented and programed. The efficiency of this scheme is tested by some example calculations. The result shows that the application of the new scheme is flexible and the correlation energy loss is lower than that of the original externally contracted CI method.     

双收缩CI方法及其应用

提出了一种近似的基于空穴-粒子对称的双收缩CI方法. 该方法一般能使组态数减少3个数量级, 计算时间减少一个数量级. 通过一系列比较计算, 表明该方法能够重现非收缩CI计算结果, 并达到了理想的计算精度.     

NH_(2-3)~(0-1 )离解能等的高级ab initio计算与评价

FeiQi等人[1]最近对H2N－H、H2N －H的离解能以及NH3、NH2的电离能，用真空紫外光电离实验进行了重新测定，并同时得到了H2N－H 的离解能．他们还在QCISD（T）／6－311＋G（3df，ZP）／／MPZ（full）／6刁IG（d）水平（GZ理论的参考水平）上对这些数据及其它相关分子的某些性质     

Configuration-based multi-reference second order perturbation theory

Various configuration-based multi-reference second order perturbation approaches were investigated and a new scheme averting intruder states was suggested. The codes based on these schemes were tested by example calculations.     

S2O分子的局域势能面和振动光谱的解析

用MRCISD和MRPT2计算了S2O分子的局域势能面，对计算点完成了力场多项式拟合和振动组态相互作用的计算.然后，对其基态(1A′)和激发态(1A′)的振动模式和振动光谱进行分析.通过调节力常数，势能面得到进一步改进.与已有的实验能谱数据进行比较，基态与激发态的均方差分别为3852cm-1和644cm-1. 关键词： S2O 势能面 能谱 MRCISD MRPT2     

NH0-1+2-3离解能等的高级ab initio计算与评价

A recent experimental determination[1] of the dissociation energies (D0) for H2N-H, H2N+-H and H2N-H+, the ionization energies for NH3 and NH2 resulted in large deviations when compared with those of the earlier values and the QCISD(T)/6-311+G(3df,2p) ab initio calculations. We have performed some higher level ab initio calculations on these data by utilizing the Gaussian 92/DFT and Gaussian 94 pakages of programs and have assessed the available experimental values. Our calculations were carried out at the QCISD (TQ)/aug-cc-pVDZ, G2(QCI), QCISD(T)/6-311 ++G(3df,3pd) and QCISD(T)/aug-cc-pVTZ levels of theory. Geometries were optimized at both of the MP2(full)/6-31G(d) and the MP2(full)/6-31(d,p) levels, and were compared with those of the experiments if available. The MP2(full)/6-31G(d,p) tight-optimized geometries for the neutrals are closer to those of the experiments than those of the MP2 (full)/6-31G(d), and are in excellent agreement with the experimental results as shown in Table 1. In this case, we assumed that the optimized geometries for the cations would be better if p polarization functions are added to the hydrogen atoms. We firstly noted that the symmetry of the NH3+ cation was D3h, other than Cs. as reported in ref.[1]. All of the zero-point energies and the final geometries are calculated at the MP2(full)/6-31G(d,p) level of theory. We have also repeated the QCISD(T )/6-311 + G(3df,2p) calculations of ref. [1], because we could not identify their level of goemetry optimization. It is found that the total energy, -55.244 19 Hartrees, for NH2+(1A1 ) in ref.[1] might be in error. Our result is -55.336 29 Hartrees at the same level of theory. At our highest level [QCISD(T)/aug-cc-pVTZ] of calculations as shown in Table 3, the D0 (temperature at zero Kelvin) values of H2N-H, H2N+-H(3B1for NH2+ ) and H2N- H+ are 4.51, 5.49 and 8.00 eV, respectively. These data reported in re f.[1] were 4.97, 5.59 and 8.41 eV, respectively. Our result on D0(H2N-H) supports the work of ref.[2,3,5,6]. The ionization energies (IE) for NH3 and NH2 (3B1 for NH2+) at our highest level are 10.11 and 11.09 eV while in ref.[1] were 10.16 and 10.78 eV, respectively. For the latter, our result supports the experiment of ref.[3]. Our predicted D0 for HN2+-H and IE for NH2 (1A1 for each NH2+) are 6.80 and 12.39 eV, respectively. These values differ greatly from the predicted values (9.29 and 14.88 eV) of ref.[1] where the total energy of NH2+(1A1) might be in error. The D0 value for HN-H has not been found in ref.[1]. Our result supports the work of ref.[3]. We have also derived all of these values at the temperature of 298K and under the pressure of 101kPa at several levels of thoery as shown in Table 3. On examining the experiment of ref.[1] in detail, it is easy to find that all of the larger deviations might be from a too high value of the appearance potential of proton AP(H+). Indeed, ref.[1] has mentioned that the determintion of AP(H+), due to kinetic shift, would lead to a hihger value for the dissociation energy as has been pointed out by Berkowitz and Ruscic. In this work, we concluded that, besides some mistakes in the theoretical calculations of ref.[1], the dissociation energies for H2N-H and H2N-H+,the IE for NH2 (3B1 for NH2+) might also be unreliable and need to be re-examined.