量子化学

Density Functional Theory method was used to optimize the geometries of 209 PCDE molecules, 209 PBDE molecules and 75 PCDD molecules at the B3LYP/6-31G* level. Using computed structural parameters as theoretical descriptors, the forward stepwise multiple regression technique was adopted to obtain QSPR models of environmental partition properties for these POPs by using GQSARF 2.0 and SPSS12.0 for windows programs. The obtained QSPR models are as follows:(1) QSPR models for predicting subcooled liquid vapor pressure, n-octanol/water partition coefficients lgK_(ow and subcooled liquid water solubilities -lgS_(w,l of PCDEs, of which correlative coefficients (R~2) are 0.988, 0.958 and 0.959 and the root-mean-square-error of estimation are 0.134, 0.116 and 0.327 respectively.(2) QSPR models of lgPL and n-octanol/air partition coefficients lgK_(oa for PBDEs, which both contain three structural parameters. The values of R2 for the two models are both 0.997 while the values of RMSEE are 0.073 and 0.062 respectively.(3) QSPR models of lgKow and–lgS_ for PCDEs, which both have one variable (mean molecular polarizability,α). The values of R~2 for the two models are 0.978 and 0.866 and the values of RMSEE are 0.300 and 0.270 respectively.(4) The molecular structures of 24 substituted naphthaline compounds were optimized using Hartree-Fock and DFT methods at four different levels and the same means was used to obtain four three-parameter (EHOMO, q~+ andα) QSPR models of lgK_. The model at the HF/6-311G** level is the best one of which R2 is 0.9662 and RMSEE is 0.380.(5) QSPR study for environmental partition properties of PCDEs was also performed using position of Cl substitution method in which simple parameters of substitution position were taken as descriptors. The multiple linear regression was performed with GQSARF 2.0 and SSPS 12.0 for windows programs to obtain QSPR models of lgP_L, lgK_ and–lgS_ for PCDEs of which R~2 are 0.991, 0.983 and 0.965 and RMSEE are 0.311, 0.100 and 0.300 respectively.

采用密度泛函理论方法在B3LYP/6-31G*水平上对PCDEs、PBDEs和PCDDs的分子结构进行了全优化计算，以计算得到的量子化学参数作为理论描述符，采用GQSARF 2.0和SPSS 12.0 for windows统计程序进行正向逐步回归分析，建立了这些POPs的环境分配性质的QSPR模型：(1) PCDEs的过冷液体蒸汽压、正辛醇/水分配系数lgK_(ow和水溶解度-lgS_(w，l的QSPR模型，这3个QSPR模型的相关系数(R2)分别为0.988、0.958和0.959，估计的均方根误差分别为0.134、0.116和0.327；(2) PBDEs的lgPL和正辛醇/空气分配系数lgK_(oa的QSPR模型，这两个模型都包含三个分子结构参数，其R~2都为0.997，RSMEE分别为0.073和0.062；(3) PCDDs类化合物的lgK_和-lgS_w的QSPR模型，两个模型都只含一个变量，其R~2分别为0.978和0.866，RSMEE分别为0.300和0.270；(4)采用Hartree-Fock和DFT方法，在4种不同水平上优化计算了24个取代萘系列化合物的分子结构，采用上述同样的方法分别建立了四种水平上的三变量lgK_模型，通过比较得到，在HF/6-311G**水平计算得到的模型最好，R为0.966，RSMEE为0.380；(5)同时，采用氯原子取代位置方法对PCDEs的环境分配性质进行QSPR研究，建立了PCDEs的lgPL、lgK_和-lgS_的QSPR模型，其R~2分别为0.991、0.983和0.965，RSMEE分别为0.110、0.100和0.300。

It requires nonconventional methodologies and strategies for Quantum chemistry to treat excited states, especially for the excited states that have the same spin multiplicity as the ground state and has no symmetry.

利用量子化学方法计算分子的激发态需要非常规的方法和策略，特别是对那些具有与基态相同的自旋多重度而又没有任何对称性的分子的较高激发态。

When two particles couple themselves in a singlet at short distances (one with spin up and one with spin down) the new nonlinear, nonlocal and nonpotential forces due to deep wave-overlappings are so attractive to overcome possible repulsive Coulomb forces, and permit new bound states at short distances which simply cannot be conceived - let alone treated - by quantum mechanics and chemistry.

当两个粒子在很小的作用距离内相互偶合成为零自旋态〔一个上旋而另一个下旋〕，深深重叠在一起的波导致新型的非线性、非局部和非潜势力的引力大到得以克服相互排斥库伦力，允许很小相互作用距离内的一种新的限制状态。量子力学和量子化学无法考虑，更不用说去处理，这种新的限制状态。

In this paper, high-level quantum chemistry calculation methods are used to theoretically investigate basic configuration, conformers, torsion potential energy surface and internal rotation transition state of oxalic acid and oxalyl halides.

第三章采用量子化学的MP2、B3LYP、HF计算方法在6-311++G~水平上，对草酸可能存在的十三种构型进行完全放开的全几何优化及振动频率分析，得到八种稳定构型和五种内转动过渡态构型。

The configuration of oxalyl fluoride neutral molecule2 is studied at HF、MP2、QCISD and B3LYP level with 6-311++G** basis sets.

方法采用量子化学中从头算的方法HF、MP2、QCISD和密度泛函中的方法B3LYP在6-311++G**水平上对草酰氟中性分子2做了构像分析，在B3LYP/6-311++G**水平上，分子轨道分析和自然键轨道分析研究了2种构型的稳定性。

ABSTRACT Investigation on the Structures and Structure-Activity Relationships for Acidic Phosphonate Rare Earth Extractants Molecular dyna...

用分子动力学模拟退火方法、半经验量子化学方法（PM3）研究了28种烃基磷酸酯系列萃取剂的三维空间结构和电子结构。

Quantum chemical CNDO/2 method has been performed to study 20 chloranlines on the electronic structure in order to analyze their toxicities to Photobacterium Phosphoreum. The correlation analysis and the step regression analysis are put in use in this paper.

研究氯苯胺类化合物的电子结构与发光菌毒性的关系，应用CNDO/2量子化学方法计算了20个氯苯胺类化合物的电子结构，探讨了发光菌在5、15、30 min时间内的半抑制浓度的负对数P(5-EC50)、P(15-EC50)、P(30-EC50)与化合物的电子结构的关系。

We explore the relation between structure and activity , structure and toxicity from electronic structure and three—dimensional conformation in order to provide theoretical foundations for predicting the activity and toxicity of these chemical compounds, researching into mechanism of action and choosing safener.

通过比较四种均三氮苯类除草剂的红外光谱特征吸收的实验值和计算值，并运用规范不变原子轨道法GIAO法在RHF/6-31G水平上计算出西玛津的δ~1H-NMR和δ~(13)C-NMR，与实验值的对比统计分析，结果表明：用RHF/6-31G优化的分子构型最佳，AM1法次之，考虑到优化时间和研究的需要，我们在研究均三氮苯类除草剂分子的结构与活性关系时，为了进行深入、精确的理论研究，采用从头算RHF/6-31G进行优化；而对于此类化合物的结构与毒性的关系研究时，更注重分子的量子化学参数的相对值而非绝对值，因而采用AM1的方法。

Our research project is focused on the synthesis, structures, spectra characterization and activity research of metal complexes with an amino-Schiff base derived from the salicylaldehyde using as SOD mimics.

本论文的研究主要集中在含有水杨醛氨基乙酸席夫碱的SOD模拟配合物的合成、结构、光谱、热分解动力学，量子化学计算以及SOD活性的测试这几个方面。

Autocorrelation topological study on the acute toxicities of substituted aromatic compound s;2. The autocorrelation topological researches on slow and acutetoxicities of substituted aromatic compound s to scenedesmus ubliquus, rat and so on;3. Results show that the SW and KOW of the substituted aromatic compound s could be better forecasted at AM1 level.

应用分子力学方法MM+和半经验量子化学AM1、MNDO和PM3法得到了54种取代芳烃的优势构象，在此基础上结合分子图形学技术，获得相应优化构象的电子结构参数和几何结构参数，并将这些参数与取代芳烃的辛醇/水分配系数和溶解度相关联。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。